Nutrients Use Efficiency in Coupled and Decoupled Aquaponic Systems
Metadata
- Cite key: aslanidouNutrientsUseEfficiency2023
- Item type: Journal Article
- Authors: M. Aslanidou, A. Elvanidi, A. Mourantian, E. Levizou, E. Mente, N. Katsoulas
- Affiliation: Laboratory of Agricultural Constructions and Environmental Control, Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Fytokou Str., 38446 Volos, Greece (Aslanidou, Elvanidi, Mourantian, Levizou, Katsoulas); Department of Veterinary Medicine, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece (Mente)
- Journal: Horticulturae 9(10) (2023) 1077 (article number, MDPI journal — not a page range)
- Date: 09/2023 (published 26 September 2023)
- Date added: 2024-02-09
- DOI: 10.3390/horticulturae9101077
- Funding: Co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, call RESEARCH–CREATE–INNOVATE (project code T1EDK-01153, acronym FoodOASIS); Ph.D. work of M. Aslanidou funded via the Center of Research Innovation and Excellence of the University of Thessaly and the Special Account of Research Grants of the University of Thessaly
- URL: https://doi.org/10.3390/horticulturae9101077
- PDF:
Aslanidou et al. - 2023 - Nutrients Use Efficiency in Coupled and Decoupled .pdf
Opinion
A methodologically careful, well-instrumented comparison (weekly RAS/NS/DS chemistry over four full crop cycles, ANOVA + Tukey–Kramer throughout) that delivers exactly what its title promises — a nutrient-flow and NUE comparison. Its major limitation for a data-extraction vault is that essentially all plant-tissue and NUE numbers are reported only as bar charts (Figures 5–8), with no companion data table, so a large share of the paper’s substantive findings cannot be captured as verifiable cell values. Worth citing for the water/NS chemistry and the CAP-vs-DCAP nutrient-solution framing, but tissue and NUE claims should be sourced back to the figures directly if precise numbers are ever needed.
Abstract
Aquaponics is currently undergoing a transformation into an intensive food production system. The initially applied systems focused on small-scale, fish-centric coupled (CAP, the aquaculture, and the hydroponic units are arranged in a single loop, and the water flows continuously from the fish tanks to the plant unit and back) aquaponics. More recently, the primary area of research interest has shifted toward larger-scale, plant-centric decoupled (aquaculture and hydroponics units are arranged in a multi-loop setup as separate functional units that can be controlled independently) systems, aiming to achieve greater economic benefits and employ more environmentally friendly practices. The objective of this study was to address gaps in the expansion of decoupled larger-scale aquaponics and to provide a comprehensive understanding of the water and nutrient flow in the system. For this purpose, experiments were performed in a greenhouse on CAP and DCAP systems, while this study also included measurements in a pure hydroponic system (HP). This study presents an assessment of the water and nutrient flow in four different crops: basil; cucumber; parsley; and tomato, all co-cultivated with a tilapia aquaculture system. Significant nutrient deficiencies and imbalances were identified in the CAP solution, leading to pronounced impacts on nutrient assimilation, particularly for fruiting vegetables. However, the average nutrient use efficiency (NUE) for nitrogen, phosphorous, potassium, and calcium was found to be 42% higher in the CAP treatment compared to HP and DCAP treatments. The nutrient solution in the DCAP treatment did not exhibit differences in water quality parameters and nutrient efficiency when compared to HP, resulting in similar effects on nutrient assimilation. Nonetheless, it was observed that DCAP plants exhibited superior NUE compared to HP plants.
Summary
The authors ran a pilot-scale greenhouse aquaponics facility in Velestino, Greece, comparing three parallel fertigation treatments — hydroponic (HP), decoupled aquaponic (DCAP), and coupled aquaponic (CAP), all sharing one red tilapia RAS — across four sequential crop cycles (basil, cucumber, parsley, tomato) between May 2020 and July 2021. Each week they measured pH, EC, and macronutrient concentrations (NO3-, NH4+, PO4, K+, Ca2+, Mg2+, SO4, Na+, Fe2+) in the RAS solution, the nutrient solution delivered to plants, and the drainage solution, then computed nutrient uptake, removal rate, and nutrient use efficiency (NUE) from those concentrations plus plant dry biomass. They found the raw CAP solution was severely nutrient-poor (down to a few percent of standard hydroponic recipe concentrations for most elements, near-zero for ammonium) and skewed in its ion ratios (low K, high Mg:K and Na:K), which translated into clear leaf/fruit nutrient deficits for CAP plants, worst in the fruiting crops (cucumber, tomato) and comparatively minor in the leafy crops (basil, parsley). The engineered DCAP solution, in contrast, was tuned weekly to match the HP recipe and showed no significant water-chemistry differences from HP. Despite its poor absolute nutrient supply, CAP plants showed the highest NUE (used a larger fraction of the little nutrient they got), while DCAP plants had higher NUE than HP for N, P and K in most crops except tomato — a difference the authors attribute to properties of the RAS-derived solution (dissolved organic matter, beneficial microbiota) that persist even after DCAP’s fertilizer top-up. The paper concludes DCAP achieves hydroponic-equivalent nutrition with a lower environmental nutrient footprint and is the more promising path for aquaponics scale-up.
Experiment data
- Location: Pilot Greenhouse Park, University of Thessaly, Velestino, Greece
- Design: 3 fertigation treatments (HP, DCAP, CAP) x 4 sequential crop cycles (basil, cucumber, parsley, tomato), 2 replicates per block, 92 plants per treatment and repetition; one shared RAS (red tilapia) supplying CAP directly and DCAP via weekly-adjusted enrichment
- Replicates / n: 2 field replicates per block per treatment (92 plants/treatment/repetition); chemical sampling n=3 per week (⚠️CHECK, see Extraction notes)
- Duration: Basil 60 d, cucumber 88 d, parsley 70 d, tomato 120 d (May 2020–July 2021 overall)
- Organisms: Red tilapia (Oreochromis spp.); Basil (Ocimum basilicum cv. Genovese), Cucumber (Cucumis sativus cv. Aisopos), Parsley (Petroselinum crispum), Tomato (Solanum lycopersicum cv. Kabrera)
- Statistics: One-way ANOVA (95% CI, p<0.05), Tukey–Kramer HSD, SPSS (IBM)
- Nutrient Use Efficiency (NUE): CAP > HP and DCAP for N, P, K, Ca (average 42% higher for CAP vs HP/DCAP per abstract); exact per-crop values reported only in Figure 8, no data table
- Nitrate (NO3): RAS solution NO3- availability 12–19% of standard recipe across crops (Table 3); CAP nutrient-solution NO3- 90.6–215.6 mg/L vs HP/DCAP ~495–695 mg/L (Tables 4–5)
Water quality and nutrient-solution chemistry
This paper’s core dataset: weekly pH and EC of RAS, nutrient solution (NS) and drainage solution (DS) per treatment and crop (Table 2); RAS nutrient availability relative to the standard recipe (Table 3); NS/DS concentrations, uptake concentration and removal rate for NO3-, NH4+, PO4, K+, Ca2+ and Na+ per treatment and crop (Tables 4–5). CAP EC was consistently around 0.9–1.3 dS/m (below the 1 dS/m minimum the authors cite as needed to avoid nutrient disorders) vs 2.0–4.1 dS/m for HP/DCAP.
Compared with:
- todo Kloas et al. 2015 — decoupled aquaponic concept this paper builds on; also reports RAS nutrient deficiencies.
- todo Monsees et al. 2017 — decoupled-systems bottleneck-elimination work cited repeatedly.
- todo Graber & Junge 2009 — reports higher HP tomato fruit potassium than DCAP, discussed as a DCAP fertilizer-adjustment caveat (p.18).
- todo Yang & Kim 2020 — first to report higher aquaponic N/P NUE vs hydroponics, corroborated here.
Plant nutrient content and NUE (not extractable to CSV)
Leaf/fruit tissue N, P, K, Ca, Na content (Figures 6–7) and NUE percentages for N, P, K, Ca, Na per crop and treatment (Figure 8), plus the standard-nutrient-ratio comparisons (Figure 5), are reported only as bar charts with error bars and significance letters — no companion data table and no values stated in running text beyond relative percentage differences (e.g., “44% higher sodium,” “phosphorous percentage difference of 55%”). Per the prime directive, none of these were read off the figures, so plant_measurements.csv receives zero rows from this paper (see Extraction notes).
Linked claims
- Coupled aquaponics produces nutrient-deficient solution relative to hydroponics
- Decoupled aquaponics can match hydroponic nutrient solution quality
- Fruiting crops are more sensitive to aquaponic nutrient deficiency than leafy crops
- RAS-derived nutrient solution may enhance nutrient use efficiency independent of concentration
Citations to chase
- todo Kloas, W. et al. (2015) — decoupled aquaponic system concept, RAS nutrient deficiency baseline
- todo Monsees, H. et al. (2017) — decoupled systems bottleneck elimination (PLoS ONE)
- todo Graber, A.; Junge, R. (2009) — DCAP vs HP tomato fruit potassium comparison
- todo Yang, T.; Kim, H.J. (2020) — N/P mass balance, aquaponic vs hydroponic NUE
- todo Delaide, B. (2017) — dissolved organic matter / PGPR hypothesis for RAS-driven NUE boost
Extraction notes
⚠️MATERIAL — Site coordinates. Methods p.3: “latitude 39°44′00″, longitude 22°79′00″” (OCR/typesetting of the original degree–minute string). Longitude minutes = 79, which is impossible (DMS minutes must be <60), so a literal DMS reading of at least the longitude cannot be correct. Reading both coordinates as decimal degrees with the degree symbol mis-placed where a decimal point belongs (39.44° N, 22.79° E) is geographically consistent with Velestino/Volos, Greece (~39.38° N, 22.75° E, a few km away — plausible for a specific greenhouse site vs. town-centre reference point), whereas reading the latitude literally as DMS (39°44′00″ = 39.7333° N) would place the site ~39 km further north than Velestino, which is not consistent. Recorded Lat = 39.44, Long = 22.79 (decimal degrees) in trials.csv; both candidate readings given here. Verify before citing precisely.
⚠️CHECK — NO3-/NH4+ reported as ionic mg/L, not as N-equivalent (NO3-N/NH4-N). Tables 1, 3, 4 and 5 all report nitrate and ammonium as the ion (NO3-, NH4+) in mg/L, e.g. basil CAP NS “NO3- 215.6 ± 55.4 mg/L,” never converted to NO3-N/NH4-N (factor ×4.43 / ×0.777 apart respectively). The paper is internally consistent in using ion units throughout, so this is not an error, but the trials.csv columns are literally named NO3-N/TAN / NH4-N. Recorded the paper’s own ionic values as-is in those columns and flagged; do not treat as nitrogen-equivalent without converting.
⚠️CHECK — “Replicates (n)” has two competing definitions in this paper. Methods p.6: “two replicates per block … 92 plants per treatment and repetition” (field/experimental-unit replication). Tables 4–5 report a separate “N” per nutrient element per treatment (18–45), which is the count of weekly chemical-sample measurements accumulated over the whole crop cycle, not field replicates. Solution sampling itself used “three sample replicates” per week (p.7). Recorded field replication (n=2 per block) in Replicates (n), as the clearest match to the schema’s “experimental units per treatment” definition; the weekly sampling counts (N=18–45) and chemical-analysis replicate count (n=3/week) are noted in Experimental Remarks per trial, not entered in the cell.
⚠️MINOR — CAP-loop nitrate mismatch between Table 3 (RAS) and Tables 4–5 (NS delivered to CAP plants). Basil: RAS NO3- 130.1 mg/L (Table 3) vs CAP NS NO3- 215.6 ± 55.4 mg/L (Table 4), a ~65% difference; cucumber similarly ~69% apart (111.3 vs 188.4 mg/L); parsley and tomato are close (92.4 vs 90.6; 113.7 vs 135.5). Since CAP is fertigated directly from the clear RAS tank, these two figures should in principle be the same measurement. The authors themselves flag and explain this (p.11): “differences may have occurred due to the remaining concentrations of nutrients in the tube network.” No cell is affected — the treatment-specific NS value from Tables 4–5 (the plant-loop value) was used for trials.csv, and the RAS-only Table 3 value was not used for any cell.
[not reported] fields, grouped:
- Fish: FCR, SGR, feed N/P/K %, % of body weight ration, fish size initial/final, total feed (kg), fish biomass created, fish survival rate, fish weight gain, fish trial duration (days) — paper reports only stocking biomass density (kg/m3) per period, never individual fish counts, weights, feed mass, or survival.
- Water: Dissolved oxygen, water temperature (NS/DS specific; only greenhouse air temperature is reported), FUE AP/HYD, WUE, water volume in the system (per-treatment attribution not stated; RAS total volume and component tank sizes given but not as a single “system volume,” see NO COLUMN below), NO2-N (never measured/reported).
- Plant: SPAD, plant height, leaf count, plant fresh weight, plant dry matter, tissue nitrate AP/HYD (paper measures total leaf N via Kjeldahl, not nitrate specifically) — none of these are reported anywhere in text or tables (see figure-only findings above for the tissue-nutrient and NUE data that IS reported, but not extractably).
- Artificial lighting, remineralization: not mentioned at all.
NO COLUMN items (in Experimental Remarks on relevant trial rows, prefixed NO COLUMN:):
- Water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3–5) — trials.csv has no water-phase columns for these ions beyond TAN/NO2-N/NO3-N.
- Uptake (absorption) concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4–5).
- Standard nutrient ratios (K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K) from Figure 5 — figure-only in any case.
- RAS system total volume (6.6–7.1 m3) and component tank sizes (3 fish tanks 1.3 m3 each, buffer tank 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer tank 2.3 m3); hydroponic-side tank sizes (6 fertigation storage tanks 500 L, 6 drainage tanks 120 L; also stated per-channel as 120 L drainage tanks in Figure 1).
- Tap water composition used for daily RAS replenishment: NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 (all mg/L).
- Daily greenhouse radiation (295.04 ± 63.97 W/m2, whole-experiment mean) and per-crop relative humidity (basil 52.48 ± 6.04%; cucumber 59.48 ± 11.26%; parsley 60.39 ± 15.98%; tomato 51.03 ± 13.25%).
- Design drainage-ratio target (30–35% of irrigated solution, cited to ref. [43]), an engineering setpoint rather than a measured exchange rate.
- Leaf/fruit tissue nutrient content and NUE percentages — figure-only, see above (also excluded from plant_measurements.csv, see next section).
Type classification rationale: Original data collected under controlled greenhouse conditions with defined treatments (HP/DCAP/CAP), randomized-block replication, and one-way ANOVA + Tukey–Kramer testing throughout (Methods §2.5, Results). Clearly experiment, confirmed by full read of Methods and Results.
plant_measurements.csv: 0 rows. All plant-tissue analyte values (leaf N/P/K/Ca/Na, fruit K/Ca/Na) and all NUE percentages are presented exclusively in bar-chart figures (Figures 5–8) with error bars and significance letters; no accompanying data table and no absolute values stated in running text (only relative percentage differences, e.g. “44% higher sodium… than the other treatments,” “phosphorous percentage difference of 55%,” which are not absolute measured values with a unit). Per the prime directive (“never read a value off a figure”), none of these were extracted. The header-only out/aslanidouNutrientsUseEfficiency2023.plant.csv reflects this.
Water panel excluded from plant_measurements.csv: all of Tables 2–5 (pH, EC, NO3-, NH4+, PO4, K+, Ca2+, Na+ in RAS/NS/DS) is water chemistry, not plant tissue, and was routed to trials.csv instead (with NO COLUMN items noted above for ions lacking a matching column).
Source: Aslanidou et al. - 2023 - Nutrients Use Efficiency in Coupled and Decoupled .pdf
Data Tables
Structured data extracted from this paper into the vault's
trials.csv/plant_measurements.csvdatasets. Fields the paper didn't report are omitted. Download the full datasets (measurements).
Trial Parameters
aslanidouNutrientsUseEfficiency2023-T1
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 5.78 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | 100 (RAS continuous recirculation loop feeding CAP directly) |
| Water type | RAS solution taken directly from the clear RAS tank, no added fertilizer (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 6.2 +/- 0.8 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 1.3 +/- 0.1 |
| TAN / NH4-N | 2.6 +/- 1.0 |
| NO3-N | 215.6 +/- 55.4 |
Plant
| Field | Value |
|---|---|
| Plant | Basil (Ocimum basilicum cv. Genovese) |
| Details | Seedlings transplanted 18 May 2020 at 2.4 plants/m2; cultivated 60 days (p.4) |
| Plant Category | Leafy (p.3) |
| Days Plant after transplant | 60 |
| Plants/m2 | 2.4 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | N (CAP fertigated directly with raw RAS solution; only acid added for pH control, no fertilizer/iron supplementation (p.6)) |
| pH Buffers | Y (pH of CAP fertigation solution adjusted with sulfuric acid (96%) for cucumber/parsley/tomato, or a mix of nitric (65%), phosphoric (85%) and sulfuric (96%) acids for basil (p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | N (No fertilizer added to CAP; plants fertigated with raw RAS solution only, drainage sterilized and returned to the aquaculture system (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and basil; CAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 26.3 +/- 2.13 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T1 = CAP treatment for basil (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | UNIT CONVERSION ONLY: RAS continuous flow rate 6 m3/h -> 100 L/min (p.4). WARN-MINOR CAP-loop NO3- mismatch: Table 3 RAS-only value (130.1 (Table 3, RAS-only value, not used for this cell)) vs Table 4/5 CAP nutrient-solution value used in this row (215.6 +/- 55.4). Authors explain (p.11): differences attributed to ‘remaining concentrations of nutrients in the tube network.’ No cell affected; NS (plant-loop) value used. | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).
aslanidouNutrientsUseEfficiency2023-T2
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 5.78 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | NR (decoupled hydroponic loop is not a continuous RAS-recycle loop; no flow rate stated for the DCAP irrigation/drainage loop) |
| Water type | Water-enriched RAS with fertilizers added weekly to reach targeted HP-equivalent nutrient solution concentrations (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 6.05 +/- 0.9 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 2.2 +/- 0.1 |
| TAN / NH4-N | 14.9 +/- 4.0 |
| NO3-N | 511.4 +/- 96.4 |
Plant
| Field | Value |
|---|---|
| Plant | Basil (Ocimum basilicum cv. Genovese) |
| Details | Seedlings transplanted 18 May 2020 at 2.4 plants/m2; cultivated 60 days (p.4) |
| Plant Category | Leafy (p.3) |
| Days Plant after transplant | 60 |
| Plants/m2 | 2.4 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | Y (Recipe includes Fe 5 umol/L (basil/parsley) or 15 umol/L (cucumber/tomato stages), added via fertilizer stock solutions per weekly RAS-analysis-adjusted recipe (Table 1, p.7)) |
| pH Buffers | Y (pH of DCAP nutrient solution adjusted via acid + fertilizer implementation in the head unit (Figure 4); specific acid type not separately stated for DCAP (only HP and CAP acid regimes detailed, p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | Y (Fertilizers added weekly to RAS-derived base solution to reach targeted Mediterranean-recipe concentrations per crop/stage (Table 1); RAS analyzed weekly for NO3-,NH4+,PO4,SO4,Ca,Mg,K,Na,Fe to set the recipe (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and basil; DCAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 26.3 +/- 2.13 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T2 = DCAP treatment for basil (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).
aslanidouNutrientsUseEfficiency2023-T3
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 8.52 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | 100 (RAS continuous recirculation loop feeding CAP directly) |
| Water type | RAS solution taken directly from the clear RAS tank, no added fertilizer (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 6.1 +/- 0.1 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 1.2 +/- 0.1 |
| TAN / NH4-N | 0.9 +/- 0.5 |
| NO3-N | 188.4 +/- 62.7 |
Plant
| Field | Value |
|---|---|
| Plant | Cucumber (Cucumis sativus cv. Aisopos) |
| Details | 15-day-old plants transplanted 21 Aug 2020 at 1.18 plants/m2; cultivated until 17 Nov 2020, 88 days (p.4) |
| Plant Category | Fruit-yielding (p.3) |
| Days Plant after transplant | 88 |
| Plants/m2 | 1.18 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | N (CAP fertigated directly with raw RAS solution; only acid added for pH control, no fertilizer/iron supplementation (p.6)) |
| pH Buffers | Y (pH of CAP fertigation solution adjusted with sulfuric acid (96%) for cucumber/parsley/tomato, or a mix of nitric (65%), phosphoric (85%) and sulfuric (96%) acids for basil (p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | N (No fertilizer added to CAP; plants fertigated with raw RAS solution only, drainage sterilized and returned to the aquaculture system (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and cucumber; CAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 25.01 +/- 3.87 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T3 = CAP treatment for cucumber (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | UNIT CONVERSION ONLY: RAS continuous flow rate 6 m3/h -> 100 L/min (p.4). WARN-MINOR CAP-loop NO3- mismatch: Table 3 RAS-only value (111.3 (Table 3, RAS-only value, not used for this cell)) vs Table 4/5 CAP nutrient-solution value used in this row (188.4 +/- 62.7). Authors explain (p.11): differences attributed to ‘remaining concentrations of nutrients in the tube network.’ No cell affected; NS (plant-loop) value used. | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).
aslanidouNutrientsUseEfficiency2023-T4
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 8.52 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | NR (decoupled hydroponic loop is not a continuous RAS-recycle loop; no flow rate stated for the DCAP irrigation/drainage loop) |
| Water type | Water-enriched RAS with fertilizers added weekly to reach targeted HP-equivalent nutrient solution concentrations (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 6.0 +/- 0.1 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 2.4 +/- 0.0 |
| TAN / NH4-N | 24.7 +/- 1.6 |
| NO3-N | 660.4 +/- 133.7 |
Plant
| Field | Value |
|---|---|
| Plant | Cucumber (Cucumis sativus cv. Aisopos) |
| Details | 15-day-old plants transplanted 21 Aug 2020 at 1.18 plants/m2; cultivated until 17 Nov 2020, 88 days (p.4) |
| Plant Category | Fruit-yielding (p.3) |
| Days Plant after transplant | 88 |
| Plants/m2 | 1.18 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | Y (Recipe includes Fe 5 umol/L (basil/parsley) or 15 umol/L (cucumber/tomato stages), added via fertilizer stock solutions per weekly RAS-analysis-adjusted recipe (Table 1, p.7)) |
| pH Buffers | Y (pH of DCAP nutrient solution adjusted via acid + fertilizer implementation in the head unit (Figure 4); specific acid type not separately stated for DCAP (only HP and CAP acid regimes detailed, p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | Y (Fertilizers added weekly to RAS-derived base solution to reach targeted Mediterranean-recipe concentrations per crop/stage (Table 1); RAS analyzed weekly for NO3-,NH4+,PO4,SO4,Ca,Mg,K,Na,Fe to set the recipe (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and cucumber; DCAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 25.01 +/- 3.87 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T4 = DCAP treatment for cucumber (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).
aslanidouNutrientsUseEfficiency2023-T5
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 8.27 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | 100 (RAS continuous recirculation loop feeding CAP directly) |
| Water type | RAS solution taken directly from the clear RAS tank, no added fertilizer (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 5.9 +/- 0.1 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 0.9 +/- 0.1 |
| TAN / NH4-N | 0.7 +/- 0.2 |
| NO3-N | 90.6 +/- 12.5 |
Plant
| Field | Value |
|---|---|
| Plant | Parsley (Petroselinum crispum (Mill.)) |
| Details | Transplanted 7 Dec 2020 at 2.4 plants/m2; cultivated 70 days (p.4) |
| Plant Category | Leafy (p.3) |
| Days Plant after transplant | 70 |
| Plants/m2 | 2.4 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | N (CAP fertigated directly with raw RAS solution; only acid added for pH control, no fertilizer/iron supplementation (p.6)) |
| pH Buffers | Y (pH of CAP fertigation solution adjusted with sulfuric acid (96%) for cucumber/parsley/tomato, or a mix of nitric (65%), phosphoric (85%) and sulfuric (96%) acids for basil (p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | N (No fertilizer added to CAP; plants fertigated with raw RAS solution only, drainage sterilized and returned to the aquaculture system (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and parsley; CAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 17.84 +/- 3.19 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T5 = CAP treatment for parsley (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | UNIT CONVERSION ONLY: RAS continuous flow rate 6 m3/h -> 100 L/min (p.4). WARN-MINOR CAP-loop NO3- mismatch: Table 3 RAS-only value (92.4 (Table 3, RAS-only value, not used for this cell)) vs Table 4/5 CAP nutrient-solution value used in this row (90.6 +/- 12.5). Authors explain (p.11): differences attributed to ‘remaining concentrations of nutrients in the tube network.’ No cell affected; NS (plant-loop) value used. | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).
aslanidouNutrientsUseEfficiency2023-T6
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 8.27 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | NR (decoupled hydroponic loop is not a continuous RAS-recycle loop; no flow rate stated for the DCAP irrigation/drainage loop) |
| Water type | Water-enriched RAS with fertilizers added weekly to reach targeted HP-equivalent nutrient solution concentrations (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 5.6 +/- 0.1 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 2.0 +/- 0.0 |
| TAN / NH4-N | 2.7 +/- 0.4 |
| NO3-N | 496.6 +/- 48.4 |
Plant
| Field | Value |
|---|---|
| Plant | Parsley (Petroselinum crispum (Mill.)) |
| Details | Transplanted 7 Dec 2020 at 2.4 plants/m2; cultivated 70 days (p.4) |
| Plant Category | Leafy (p.3) |
| Days Plant after transplant | 70 |
| Plants/m2 | 2.4 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | Y (Recipe includes Fe 5 umol/L (basil/parsley) or 15 umol/L (cucumber/tomato stages), added via fertilizer stock solutions per weekly RAS-analysis-adjusted recipe (Table 1, p.7)) |
| pH Buffers | Y (pH of DCAP nutrient solution adjusted via acid + fertilizer implementation in the head unit (Figure 4); specific acid type not separately stated for DCAP (only HP and CAP acid regimes detailed, p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | Y (Fertilizers added weekly to RAS-derived base solution to reach targeted Mediterranean-recipe concentrations per crop/stage (Table 1); RAS analyzed weekly for NO3-,NH4+,PO4,SO4,Ca,Mg,K,Na,Fe to set the recipe (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and parsley; DCAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 17.84 +/- 3.19 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T6 = DCAP treatment for parsley (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).
aslanidouNutrientsUseEfficiency2023-T7
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 9.77 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | 100 (RAS continuous recirculation loop feeding CAP directly) |
| Water type | RAS solution taken directly from the clear RAS tank, no added fertilizer (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 5.8 +/- 0.1 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 1.1 +/- 0.0 |
| TAN / NH4-N | 1.1 +/- 0.1 |
| NO3-N | 135.5 +/- 2.7 |
Plant
| Field | Value |
|---|---|
| Plant | Tomato (Solanum lycopersicum cv. Kabrera) |
| Details | Transplanted 15 Mar 2021 at 1.76 plants/m2; cultivated until 13 Jul 2021, 120 days (p.4) |
| Plant Category | Fruit-yielding (p.3) |
| Days Plant after transplant | 120 |
| Plants/m2 | 1.76 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | N (CAP fertigated directly with raw RAS solution; only acid added for pH control, no fertilizer/iron supplementation (p.6)) |
| pH Buffers | Y (pH of CAP fertigation solution adjusted with sulfuric acid (96%) for cucumber/parsley/tomato, or a mix of nitric (65%), phosphoric (85%) and sulfuric (96%) acids for basil (p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | N (No fertilizer added to CAP; plants fertigated with raw RAS solution only, drainage sterilized and returned to the aquaculture system (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and tomato; CAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 24.9 +/- 3.74 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T7 = CAP treatment for tomato (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | UNIT CONVERSION ONLY: RAS continuous flow rate 6 m3/h -> 100 L/min (p.4). WARN-MINOR CAP-loop NO3- mismatch: Table 3 RAS-only value (113.7 (Table 3, RAS-only value, not used for this cell)) vs Table 4/5 CAP nutrient-solution value used in this row (135.5 +/- 2.7). Authors explain (p.11): differences attributed to ‘remaining concentrations of nutrients in the tube network.’ No cell affected; NS (plant-loop) value used. | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).
aslanidouNutrientsUseEfficiency2023-T8
Fish
| Field | Value |
|---|---|
| Fish | Red tilapia (Oreochromis spp.) |
| Initial Stock density | 9.77 |
| Protein | 29.0 |
| Feed routine | Hand-fed to satiation, three times per day (p.5) |
| Feed regime | Prodac Pondsticks Color: crude protein 29.0%, crude ash 5.7%, crude fibers 3.3%, crude fat 2.9%, moisture 4.8%, omega 6 42.2%, omega 3 5.7% (p.5) |
Water
| Field | Value |
|---|---|
| Water recycle | NR (decoupled hydroponic loop is not a continuous RAS-recycle loop; no flow rate stated for the DCAP irrigation/drainage loop) |
| Water type | Water-enriched RAS with fertilizers added weekly to reach targeted HP-equivalent nutrient solution concentrations (p.6) |
| Daily Water exchange rate | 3.3-16.9 (daily RAS replenishment range across the whole experiment; not resolved per individual crop period, p.4) |
| Aq pH | 5.9 +/- 0.0 |
| pHOptimal | 5.5-6.5 (literature-cited acceptable NS pH range, Discussion p.17 ref. 56; not a treatment-specific setpoint) |
| EC | 2.9 +/- 0.1 |
| TAN / NH4-N | 22.5 +/- 1.0 |
| NO3-N | 691.8 +/- 17.7 |
Plant
| Field | Value |
|---|---|
| Plant | Tomato (Solanum lycopersicum cv. Kabrera) |
| Details | Transplanted 15 Mar 2021 at 1.76 plants/m2; cultivated until 13 Jul 2021, 120 days (p.4) |
| Plant Category | Fruit-yielding (p.3) |
| Days Plant after transplant | 120 |
| Plants/m2 | 1.76 |
System & Setup
| Field | Value |
|---|---|
| System type | Perlite-slab hydroponic channels, drip irrigation (media-based technique) |
| Media Details | Perlite slabs (Isocon Perloflor Hydro 1, Isocon S.A.), 8 slabs per channel, 18 channels (~8 m x 0.22 m) in 3 blocks, channels elevated 50 cm; drip irrigation via spaghetti tubes/angle drippers, 5 drippers per slab, 2.3 L/h per dripper (p.3-4) |
| Biological system already in use | Y (RAS mechanical filter (Combi Bio 15, 0.5 m3) + biological filter (ceramic rings 15mm and K1 Kaldnes media 1mm, 0.7 m3) upstream of clear buffer tank (p.3)) |
| Air supplement | Y (Air blower (ASC-Standard, Airtech Europe GmbH, 100 m3/h) via four-inch air diffusers (KW ZONE) to RAS tanks (p.4)) |
| Iron supplemented | Y (Recipe includes Fe 5 umol/L (basil/parsley) or 15 umol/L (cucumber/tomato stages), added via fertilizer stock solutions per weekly RAS-analysis-adjusted recipe (Table 1, p.7)) |
| pH Buffers | Y (pH of DCAP nutrient solution adjusted via acid + fertilizer implementation in the head unit (Figure 4); specific acid type not separately stated for DCAP (only HP and CAP acid regimes detailed, p.6-7)) |
| Climate control | Y (Climate-controlled greenhouse; air temperature/RH recorded via iMETOS sm system (Pessl Instruments) and automatically controlled via climate control computer (Emmanouilidis, Thessaloniki) (p.4)) |
| Nutrient supplemented | Y (Fertilizers added weekly to RAS-derived base solution to reach targeted Mediterranean-recipe concentrations per crop/stage (Table 1); RAS analyzed weekly for NO3-,NH4+,PO4,SO4,Ca,Mg,K,Na,Fe to set the recipe (p.6)) |
| Equipment | Jet pump 83 L/min (RAS recirculation, Aquastrong); air blower ASC-Standard 100 m3/h; mechanical filter Combi Bio 15 (0.5 m3); biological filter (ceramic rings 15mm + K1 Kaldnes media 1mm, 0.7 m3); pH/EC transducer (GHM-Greisinger); pressure sensor (WIKA); portable Hanna Combo pH-EC-TDS-Temp; Hach HQ40d pH meter; Hach DR3900 spectrophotometer (NO3-/NH4+/PO4); Flame photometer Jenway PFP7 (K+/Ca2+/Na+); Libra S11 spectrophotometer (P); custom fertigation controller (Argos Electronics); iMETOS sm climate sensor; climate control computer (Emmanouilidis) (p.3-7) |
| Control Parameters | 3 treatments (HP, DCAP, CAP) x 3 blocks x 2 replicates/block, 92 plants/treatment/repetition; weekly RAS/NS/DS chemistry sampling, 3 sample replicates/week; one-way ANOVA + Tukey-Kramer HSD, p<0.05 (p.5-8) |
| Combination | Red tilapia and tomato; DCAP vs HP (perlite media, drip irrigation) |
Site
| Field | Value |
|---|---|
| Region | Europe |
| Country | Greece |
| Lat | 39.44 |
| Long | 22.79 |
| Average room Temperature | 24.9 +/- 3.74 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | mg/L (NS/DS/RAS nutrient concentrations, ion form); dS/m (EC); pH units |
| Statistic Details | One-way ANOVA, 95% CI (p<0.05), Tukey-Kramer HSD test, SPSS (IBM), 2012 (p.8) |
| Statistically analysed | Y |
| Replicates (n) | 2 |
Experimental Remarks: TRIAL DEFINITION: aslanidouNutrientsUseEfficiency2023-T8 = DCAP treatment for tomato (one of 3 parallel fertigation treatments per crop: HP, DCAP, CAP, 2 replicates/block, 92 plants/treatment/repetition). Paired control = HP (100% standard fresh nutrient solution), recorded via the HYD-side convention in Extraction notes; HP itself does not get its own row since it is not an aquaponic treatment. All three treatments share the same red tilapia RAS (p.6). | WARN-CHECK NO3-/NH4+ recorded as ionic mg/L (NO3-, NH4+) per the paper’s own units, not converted to N-equivalent (NO3-N/NH4-N, factor x4.43/x0.777); trials.csv column names imply N-equivalent but the paper never reports that form. Recorded as-is. See paper note for full evidence. | WARN-MATERIAL Lat/Long: Methods p.3 gives ‘latitude 39 deg 44’ 00”, longitude 22 deg 79’ 00”’. Longitude minutes=79 is impossible DMS (>59). Read both as decimal degrees (39.44, 22.79) -> consistent with Velestino/Volos, Greece (~39.38N, 22.75E); literal DMS latitude (39.7333) would be ~39 km further north, inconsistent. Recorded decimal reading. See paper note for full reasoning. | WARN-CHECK Replicates (n): field design states ‘two replicates per block, 92 plants per treatment and repetition’ (p.6) -> recorded as 2. Tables 4-5 also report a per-element sample count N=18-45 (repeated weekly chemical measurements over the crop cycle, not field replicates); weekly solution sampling itself used 3 sample replicates (p.7). All three are different things; field replicate count (2) recorded in the cell. | NO COLUMN: water-phase K+, Ca2+, Na+, Mg2+, PO4^2-, SO4^2- and Fe2+ concentrations in RAS/NS/DS (Tables 3-5) have no matching trials.csv column beyond TAN/NO2-N/NO3-N. NO COLUMN: uptake/absorption concentration (Cu, mg/L) and removal rate (RM, mg/g dry biomass) per nutrient per treatment (Tables 4-5). NO COLUMN: standard nutrient ratios K+:[K+Ca+Mg], Ca:[K+Ca+Mg], Mg:[K+Ca+Mg], NH4+NO3:K, NH4:[NH4+NO3], PO4:[NH4+NO3], Na:K (Figure 5, figure-only). NO COLUMN: RAS total volume 6.6-7.1 m3 and component tanks (3 fish tanks 1.3 m3 each, buffer 0.7 m3, mechanical filter 0.5 m3, biofilter 0.7 m3, clear buffer 2.3 m3); hydroponic-side tanks (6 fertigation storage 500 L, 6 drainage 120 L). NO COLUMN: tap water composition used for daily RAS replenishment (NO3- 17.7, NH4+ 0.09, PO4 0.18, SO4 9, Fe 0.021, Ca 31, Mg 39.1, K 3, Na 35 mg/L, p.4). NO COLUMN: daily greenhouse radiation (295.04 +/- 63.97 W/m2, whole-experiment mean) and per-crop relative humidity. NO COLUMN: design drainage-ratio target 30-35% of irrigated solution (ref. 43), an engineering setpoint not a measured exchange rate. NO COLUMN: leaf/fruit tissue nutrient content (Figures 6-7) and NUE % (Figure 8) are figure-only, see note and plant.csv (0 rows).