System management of Lemna minor in aquaponics

Metadata

• Cite key: camargocastellanosSystemManagementLemna2022
• Item type: Journal Article
• Authors: Juan Carlos Camargo-Castellanos, Luis Flores-García, Israel Enrique Herrera-Díaz, Carlos A. Álvarez-González, Pedro J. Albertos-Alpuche, Rosario Martínez-Yáñez
• Affiliation: Biosciences Doctoral Program, Universidad de Guanajuato, Irapuato, Mexico; Aquaculture Laboratory, Universidad de Guanajuato, Irapuato, Mexico; Tropical Aquaculture Laboratory, DACBIOL-UJAT, Villahermosa, Mexico
• Journal: Aquaculture Research 53 (2022) 974-988
• Date: 02/2022 (Received 17 May 2021; Revised 8 October 2021; Accepted 12 October 2021)
• Date added: [not reported]
• DOI: 10.1111/are.15637
• Funding: “This research received internal funding (UG).”
• URL: https://doi.org/10.1111/are.15637
• PDF: Camargo‐Castellanos et al. - 2022 - System management of Lemna minor in aquapon.pdf

Opinion

A genuinely useful engineering-parameters paper — there is very little published on HRT and planting-density management specifically for a floating macrophyte (as opposed to leafy vegetables) in aquaponics, and the three-experiment funnel design (screen HRT, screen planting density, then run a full mass-balance at the two best levels) is a sensible way to answer that. The mass-balance work in Experiment 3 (Tables 1-5) is careful and internally consistent (I cross-checked several totals against their components and they reconcile). The weak point is Experiments 1 and 2: despite being replicated (n=3) and analysed with ANOVA/Tukey like Experiment 3, their actual production and growth results are presented only as bar charts (Figure 3) and a line graph (Figure 5) — no table, no in-text numbers — so most of that data is unusable for anything beyond “which level won.” Anyone wanting the numbers behind the paper’s central HRT/PD recommendation (30 min, 300 g/m2) has to go back to the authors. I would cite this for the mass-balance figures and the qualitative HRT/PD conclusions, but not for exact HRT/PD production values, which simply aren’t published.

Abstract

In farming, sustainability together with food safety is one of the main objectives to be achieved. Aquaponics is a technique that combines aquatic animals, such as fish, with the hydroponic production of plants that function as biological filters. The proper functioning of the system is based on the dynamic balance of the elements that make it up. Several studies confer aquatic macrophytes such as L. minor, great attributes, highlighting their use for feeding different species. Unfortunately, there is very little information on the system management of macrophytes in aquaponics. To determine the appropriate management parameters for the cultivation of L. minor integrated into the production of Oreochromis niloticus, in aquaponics, three experiments were carried out to evaluate the effect of the hydraulic retention time (HRT), the planting density, plant dissemination and the balance of nutrients in the systems. The results show that the highest biomass production and plant growth are achieved with high flow rates and short HRTs. Planting density has a direct effect on the behaviour of the plant. Regarding the balanced budget, between 7% and 8% of the nutrients (input in dry matter, N and P) are retained by L. minor, keeping the water quality within adequate limits for tilapia production.

Summary

The authors ran three linked experiments at the University of Guanajuato (Irapuato, Mexico) to work out system-management parameters for growing the floating macrophyte Lemna minor (duckweed) integrated with Nile tilapia. Experiment 1 screened six hydraulic retention times (15-90 min) and Experiment 2 screened six planting densities (50-300 g/m2 fresh matter), each replicated three times (n=3), each using a shared 18-bed recirculating system; both found that a short HRT (30 min) and a high planting density (300 g/m2) gave the greatest biomass production, growth rate and plant dissemination (canopy cover). Experiment 3 then used those two “winning” settings across nine independent, smaller aquaponic systems to test three planting areas (5, 6 and 7 m2 per system, n=3 each), measuring full dry-matter, nitrogen and phosphorus mass balances across fish, plants, sludge and water. The 5 m2 treatment gave the highest per-m2 biomass yield, while a 6 m2 treatment gave a (non-significant) edge in overall nutrient-retention efficiency. Across the whole study, L. minor retained roughly 6-9% of the daily N and P fed to the system, fish incorporated 22-46%, and the remainder went to sludge, dissolved water and unaccounted losses; water quality (pH ~7.5-7.7, DO ~5.6 mg/L, EC ~1.6-1.8 mS/cm3) stayed within ranges suitable for both tilapia and duckweed throughout. No fish mortality or notable welfare problems were observed in any of the three experiments.

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Experiment data

• Location: Aquaculture Laboratory, Veterinary and Zootechnical Department, University of Guanajuato, Irapuato, Mexico (20°44’34.42” N, 101°19’50.7” W; 1,745 m a.s.l.) — stated explicitly for Experiments 1-2 only; not restated for Experiment 3 (see Extraction notes).
• Design: Exp 1 — one-way, 6 HRT levels (15/30/45/60/75/90 min), n=3 HBs/level. Exp 2 — one-way, 6 planting-density levels (50/100/150/200/250/300 g/m2 FM), n=3 HBs/level, run at the HRT selected from Exp 1. Exp 3 — one-way, 3 planting-area levels (5/6/7 m2), n=3 independent systems/level, run at the HRT and planting density selected from Exp 1-2, with full DM/N/P mass balance.
• Replicates / n: 3 per treatment level in all three experiments.
• Duration: Exp 1: 9 days. Exp 2: 7 days. Exp 3: 10 days. Each of Exp 1-2 ended when canopy cover exceeded 90% in any hydroponic bed.
• Organisms: Nile tilapia (Oreochromis niloticus) / Lemna minor (duckweed)
• Statistics: Exp 1-2: one-way ANOVA, Cochran test (homogeneity/normality), Tukey’s test (p<0.01); plant dissemination analysed via a repeated-measures mixed linear model. Exp 3: one-way ANOVA, Bartlett test, Bonferroni test.
• Hydraulic retention time: Highest biomass production, growth and dissemination at 30 min (of 15-90 min tested) — qualitative ranking only; no table/text values, see Extraction notes.
• Planting density: Highest biomass production, growth and dissemination at 300 g/m2 (of 50-300 g/m2 tested) — same figure-only caveat.
• Plant fresh weight (areal, Table 1): 609.73 +/- 14.75 g/m2 (5 m2) > 568.01 +/- 12.69 g/m2 (6 m2) > 477.97 +/- 6.32 g/m2 (7 m2)
• N and P retention by plants (Table 4): N 6.06-6.77%, P 7.67-8.58% of daily feed input, across the three planting areas

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Hydraulic retention time (Experiments 1 & 3)

This paper: Of six HRT levels tested (15-90 min), 30 min gave the highest fresh matter, dry matter, organic matter, crude protein production and relative growth rate (RGR), and the highest plant dissemination (%) (Figure 3-5; p.5). The authors attribute this to L. minor being a surface-floating plant whose growth depends on root-zone contact time and dissolved-oxygen exposure at the water surface, rather than substrate penetration. This 30-min HRT was then carried forward into Experiments 2 and 3.

Compared with:

• todo Endut et al. 2010 — best HRT for Ipomoea aquatica (a semi-aquatic, substrate-rooting plant) with Clarias gariepinus was 62.5 min, much longer than this paper’s 30 min optimum for the floating, non-rooting L. minor. (p.7)
• todo Wang et al. 2016 — comparing three floating plants (Pistia stratiotes, Lemna minor, Eichhornia crassipes) on COD removal from sewage, optimal residence times were 14 d, 8 d and 10 d respectively; L. minor removed nitrogen compounds faster than E. crassipes at lower HRT, consistent with this paper’s short-HRT finding. (p.8)
• todo Arias et al. 2016 — L. minor phytoremediation of Furcraea bedinghausii fibre-washing wastewater was more efficient at 8-day HRT than 10-day HRT, supporting a “short HRT, high flow” hypothesis for this species in RAS-type systems. (p.8)
• todo Yang and Kim 2020 — Brassica rapa and Lactuca sativa performed best in aquaponics at high/medium flow rates (3.33 and 2.22 m3/m2/day), which the authors calculate as roughly equivalent to 45-60 min HRT in their own system — i.e. still longer than L. minor’s 30-min optimum. (p.8)

Planting density and plant dissemination (Experiment 2)

This paper: RGR increased directly with planting density up to the highest level tested (300 g/m2); plant dissemination (canopy cover, %) likewise increased with density and with days elapsed. The authors note a “crowding” phenomenon (daughter fronds growing beneath mother fronds, driving colour change and frond death once an HB is fully covered), and recommend harvesting once canopy cover approaches 90-100% rather than letting density climb further.

Compared with:

• todo Driever et al. 2005 — under lab conditions (23°C, vertical 2 L cylinders, nutrient-replete medium), RGR became negative above 180 g DM/m2 and peaked (0.3 day-1) at 9 g DM/m2; the present study’s peak RGR (0.245 day-1 at 23.5 g DM/m2, i.e. 300 g FM/m2) is lower and occurs at a higher density, which the authors extrapolate to imply a negative-RGR threshold around 380 g FM/m2 in their own system (not tested). (p.9)
• todo Njambuya et al. 2011 — L. minor outcompetes L. minuta in low-nutrient environments even at double the L. minuta biomass, a competitive advantage that reverses at medium-high nutrient concentrations. Cited as context for why crowding/competition dynamics matter for duckweed management generally. (p.9)

Planting area and dry-matter/N/P mass balance (Experiment 3)

This paper: Across 5, 6 and 7 m2 of planting area (with HRT and planting density fixed at the Exp 1-2 optima), the 5 m2 treatment gave the highest per-m2 fresh/dry/organic matter and crude protein yield and RGR; growth (RGR) did not differ significantly between 5 and 6 m2. Considering whole-system totals (summing across all HBs per system) there were no significant differences in biomass production between the three areas, though nutrient-retention efficiency showed a slight (non-significant) edge for 6 m2: fish incorporated 22.6-23.7% of daily N and 44.2-46.4% of daily P; plants retained 6.1-6.8% of N and 7.7-8.6% of P; sludge captured 22.7-24.0% of N and 23.0-24.4% of P; the balance went to dissolved water (21.8-24.1% N; ~1% P) and unaccounted losses (22.6-25.6% N; 21.0-22.6% P). Bromatological analysis of the harvested duckweed gave 7.75% dry matter, 30.0% crude protein, 34.16% NDF, 15.88% ADF, 6.07% lignin, 19.77% ash, 2.02% Ca and 1.1% P (reported once for the whole experiment, not split by planting area).

Compared with:

• todo Ge et al. 2012 — L. minor grown in pig-production wastewater produced 3.5 g DM/m2/day, well below this study’s 47.25 g DM/m2/day (5 m2 treatment), attributed to aquaponics providing more continuously available nutrients than wastewater. (p.10)
• todo Chakrabarti et al. 2018 — L. minor mass production in an unspecified system gave 2.34 g DM/m2/day, again well below this study’s figures. (p.10)
• todo Zhao et al. 2014 — L. japonica in outdoor ponds/impacted water bodies produced 18.22 g DM/m2/day; Cheng et al. 2002 reported 28.19 g DM/m2/day for L. minor in swine lagoon liquid — both higher than this study, attributed by the authors to different nutrient concentrations and pH in those systems. (p.11)
• todo Trang and Brix 2014 — reported N and P retention in fish of 43% and 73% respectively (vs this study’s 22-24% N, 44-46% P), and roughly 7% biomass-nutrient retention across three plant species combined (Ipomoea aquatica, Lactuca sativa, Canna glauca), used to argue L. minor is comparatively more efficient at removing suspended water nutrients than those three species. (p.9,11)
• todo Thuy-Diem et al. 2017 — reported N and P absorption of 35% and 45% respectively in a similar system; the higher N figure vs this study is attributed to their fish being smaller (54 g) at stocking, since smaller fish grow faster and assimilate more feed nitrogen. (p.11)
• todo Rafiee and Saad 2005 — in tilapia generally, only 40-43% of feed is assimilated into flesh, the rest excreted; this study’s 16-17% dry-matter-to-fish-biomass conversion is lower still, attributed to the short trial duration and larger initial fish size (SGR 1.4% animal/day). (p.11)
• todo Appenroth et al. 2017 — 25% crude protein in L. minor under lab conditions, vs Bergmann et al. 2000 13.4% under similar conditions — both below this study’s 30.0% CP, attributed to nutrients being continuously dissolved and available for root uptake in aquaponics. (p.10)
• todo Capriotti et al. 2018 — RGR of 0.349 for L. minor in a commercial salts/sucrose mixture, close to this study’s 0.385 (5 m2, per-area basis); Iatrou et al. 2018 reported 0.190 and Basiglini et al. 2018 0.091 for L. minor/L. gibba in treated/untreated industrial waters respectively — both lower, attributed to lower nutrient demand availability in those systems. (p.10, p.12)

Linked claims

• Lemna minor performs best in aquaponics at short hydraulic retention time and high flow rate, unlike substrate-rooting plants
• Planting density in duckweed aquaponics trades off biomass production against crowding-driven frond mortality
• Duckweed retains a smaller share of system nitrogen and phosphorus than fish, but is comparatively efficient among plant biofilter species

Citations to chase

• todo Endut et al. (2010) — HRT optimisation for Ipomoea aquatica with Clarias gariepinus, contrasting root-zone vs floating plant HRT response
• todo Wang et al. (2016) — comparative HRT/purification performance of Pistia stratiotes, Lemna minor and Eichhornia crassipes on sewage
• todo Arias et al. (2016) — L. minor phytoremediation of sisal-fibre wastewater at 8 vs 10-day HRT
• todo Yang and Kim (2020) — N/P mass balance and flow-rate optimisation in tomato/basil/lettuce aquaponics vs hydroponics
• todo Driever et al. (2005) — density-dependent RGR limits in L. minor under lab conditions
• todo Njambuya et al. (2011) — competitive dynamics between L. minor and L. minuta across nutrient gradients
• todo Ge et al. (2012) — L. minor biomass yield in pig-production wastewater
• todo Chakrabarti et al. (2018) — L. minor mass production, amino/fatty acid profiling
• todo Zhao et al. (2014) — L. japonica biomass yield in outdoor ponds, pilot-scale comparison with water hyacinth
• todo Cheng et al. (2002) — L. minor nutrient removal and biomass yield from swine lagoon liquid
• todo Trang and Brix (2014) — planted biofilter N/P mass balance in integrated RAS-hydroponics, Mekong Delta
• todo Thuy-Diem et al. (2017) — recirculation rate effects on water quality and O. niloticus growth in aquaponics
• todo Rafiee and Saad (2005) — nutrient cycling and sludge production across tilapia growth stages in RAS
• todo Appenroth et al. (2017) — nutritional value of duckweeds as human food, protein benchmark
• todo Bergmann et al. (2000) — duckweed geographical isolates for swine lagoon effluent renovation, protein content
• todo Capriotti et al. (2018) — L. minor growth rate in commercial salts/sucrose culture medium
• todo Iatrou et al. (2018) — L. minor/L. gibba biomass, protein and starch in treated industrial wastewater
• todo Basiglini et al. (2018) — duckweed growth/enzymatic response in untreated industrial wastewater

Extraction notes

Severity tally: 0 ⚠️BLOCK, 0 ⚠️MATERIAL, 1 ⚠️CHECK, 4 ⚠️MINOR → quality: ok (per SCHEMA.md: 0 BLOCK and <=2 MATERIAL qualifies as ok; CHECK and MINOR never affect the score).

• ⚠️CHECK — Relative growth rate (RGR) reported under two different, unstated bases, and duckweed’s RGR metric has no dedicated schema column. Table 1 gives RGR computed from per-planting-area production (5/6/7 m2: 0.385/0.378/0.361 day-1); Table 2 (“Total production and growth”) gives RGR computed from whole-system absolute production (0.546/0.557/0.555 day-1). Both use the identical formula from Methods 2.1.3e (RGR = ln(DM produced)/days) but differ in whether “DM produced” is the per-m2 or whole-system figure, and the paper never states which is “the” RGR for comparison against other studies (the Discussion section quotes the per-m2 figure, 0.385, against literature values, without flagging that a second whole-system figure also exists). This is exactly the duckweed relative-growth-rate ambiguity anticipated for this species — recorded as NO COLUMN reference values in Experimental Remarks for all of T3-T5 (T1 remarks flag it once as a general note) rather than force-fit into any cell, since no RGR column exists in the schema anyway.
• ⚠️MINOR — Table 1’s RGR column header prints “RGR / m2 day-1”, but Methods 2.1.3e defines RGR (day-1) as a pure per-day rate with no area term. Read as a table-layout artefact (the “m2” appears to bleed over from the adjacent “Organic matter g m2” column header) rather than a genuine second unit; no numeric impact, values transcribed as printed.
• ⚠️MINOR — Abstract/Conclusions round the plant nutrient-retention figure to “between 7% and 8%” for combined “dry matter, N and P”, but the more precise in-text statement (Section 4.3, p.11) and the per-treatment Table 3/4 values show DM retention at 7.67-8.58% and P retention at 7.67-8.58% (both consistent with “7-8%”), while N retention is actually 6.06-6.77% (below the abstract’s stated floor). The precise Table 3/4 per-treatment values are used in every trials.csv cell regardless, so no cell is affected — this is a rounding/summarising imprecision in the Abstract, not a genuine numeric conflict.
• ⚠️MINOR — Feed N-to-protein cross-check (Experiment 3): Table 4 footnote a states the feed was 6.08% N in dry matter; applying the standard Kjeldahl N x 6.25 factor gives 38.0% crude protein, versus the diet’s nominal “35% crude protein” label given for Experiment 2’s feed (Section 2.1.2) and presumably reused for Experiment 3 per the “management of the fish was like the previous experiments” statement (p.4). An ~8.6% relative gap, plausibly explained by feed-lot variation or a non-6.25 N-to-protein factor for this diet; not flagged as a genuine conflict since the two figures come from different sources (a manufacturer/nominal label vs a directly-assayed feed N%), and both are recorded in trials.csv as given (Protein=35, N=6.08).
• ⚠️MINOR — Fish stocking arithmetic check (Experiment 3): 100 fish x 136.95 g stated mean initial weight = 13,695 g = 13.695 kg, versus the stated total pond biomass of 13.89 +/- 0.50 kg (a ~1.4% difference, well within the paper’s own reported 3.6% CV across the 9 ponds). Both figures are plausibly correct as different aggregations (a grand mean across all 900 individual fish vs a mean of the 9 individual pond totals); recorded as given, not flagged as a conflict.

[unclear] fields (grouped by issue, not by column, since several columns are affected by the same underlying gap):

• Feed composition/rate for Experiment 1: the diet description (35% CP, 7% ether extract, 5% crude fibre, 13% ash, 25.8% NFE, fed at 3% body weight/day) is grammatically attached only to the sentence introducing Experiment 2’s fish cohort (p.3); Experiment 1’s fish (215 individuals) are introduced in the preceding sentence with no feed description attached. Recorded NR for T1’s Protein/N/P/K/% of body weight/Feed routine/Feed regime rather than assumed identical to Experiment 2.
• Basis for Experiments 1-2’s crude-protein (CP) production figures: the study-variable formula “CP in DM = DM x %CP” (Section 2.1.3d) requires a %CP input, but the chemical/bromatological analysis method that measures %CP (Section 2.2.4) is described only for Experiment 3; Figure 3 nonetheless reports g/m2 CP values for Experiments 1-2. The source of the %CP figure used there is not stated. Since Figure 3’s values are unusable anyway (bar chart, no printed numbers), this doesn’t block a cell, but it does mean the CP figures shown in Figure 3 for Experiments 1-2 cannot be traced to a stated measurement method.
• Site coordinates for Experiment 3: GPS coordinates (20°44’34.42” N, 101°19’50.7” W) are given explicitly only in the Experiment 1-2 system description (Section 2.1.1); Experiment 3’s system description (Section 2.2.1) does not restate a location. The paper’s author affiliations span two different Mexican institutions (Universidad de Guanajuato, Irapuato, and DACBIOL-UJAT, Villahermosa), so the specific facility for Experiment 3 cannot be confirmed. Lat/Long left NR for T3-T5; Region/Country recorded as North America/Mexico since both candidate institutions are Mexican.
• EC threshold for Experiment 2’s plantings: an EC=1.4 mS/cm3 planting-timing threshold is stated for Experiment 1 (p.3) but not restated for Experiment 2’s varying-density plantings (Experiment 3 separately and explicitly states its own threshold, 1.5 mS/cm3). Not assumed to carry over; T2’s Control Parameters omits an EC threshold rather than reusing Experiment 1’s value.

[not reported] fields, grouped by field (all trials unless noted): Fish Category; Initial Stock density (component numbers given for Experiment 3 — 13.89 kg/pond, 1 m3 VEf — but the density itself is never printed); FCR; Fish size final (all trials); Fish weight gain; Total Feed (kg) for T1-T2 (only a daily % rate is given, no cycle total); Fish biomass created (kg); Water type; Water classification; Daily Water exchange rate; pHOptimal; FUE AP; WUE; NO2-N (never measured/reported in any of the three experiments — only NH4+ appears in the water-quality table); NO3-N (water) (not measured directly as a discrete species; only total dissolved N/P are given in the Table 4 mass balance); Plants/m2 (Lemna is a mass-planted floating species, not planted at a per-plant density — routed to NO COLUMN as g/m2 biomass instead); SPAD; Tissue nitrate AP/HYD (the paper measured total tissue N/P/Ca and proximate composition, never nitrate specifically); Average room Temperature; Biological system already in use; Iron supplemented; Remineralization; pH Buffers; Artificial Lighting; Nutrient supplemented; Water volume in the system for T1-T2 (individual compartment volumes given — pond 3.6 m3, clarifier 0.4 m3, biofilter 1.0 m3, 18 HB x 0.1 m3 — but no stated aggregate; summing would be derivation).

Duckweed-specific schema mismatches (flagged per the extraction brief, not treated as paper defects): Plant height and Leaf count are recorded NA throughout — L. minor has no stem separate from the leaves (fused into a single “frond” structure, explicitly stated p.2) and the paper never reports discrete frond counts. Plant fresh weight and Plant dry matter (g/plant, %) are NR for T1-T2 and largely routed to NO COLUMN even for T3-T5, since the paper’s actual metrics are areal (g/m2, g/system) and relative growth rate (day-1), not per-plant weights — the one genuine %-dry-matter figure that does exist (7.75%, Section 3.2) is entered in the Plant dry matter column for T3-T5 only, since it is a true percentage composition value, unlike the areal production figures.

Scanned PDF check: this PDF has a clean, searchable text layer (native digital typesetting via Wiley/Aquaculture Research); no OCR issue, not added to NEEDS_OCR.md.

New tags introduced: Meta/Plant/Lemna-Minor (new — no existing Lemna/duckweed facet in the vault; capitalisation follows the existing two-word convention seen in Meta/Plant/Indian-Spinach). Meta/Type/Experiment, Meta/Fish/Tilapia reused from existing vault entries (e.g. lenzCommonChicoryProduction2021, aljenaidNutrientFilmTechnique2026). Meta/Region/North-America is new — no existing note yet covers Mexico/North America; the existing region leaves are South-America, Middle-East, Africa, South-Asia.

New wikilink targets introduced: Juan Carlos Camargo-Castellanos, Luis Flores-García, Israel Enrique Herrera-Díaz, Carlos A. Álvarez-González, Pedro J. Albertos-Alpuche, Rosario Martínez-Yáñez, Nile tilapia (Oreochromis niloticus) (checked — appears to already exist as a claim/link target from lenzCommonChicoryProduction2021, reused rather than duplicated), Lemna minor (duckweed), Hydraulic retention time, Planting density, Plant fresh weight (reused from lenzCommonChicoryProduction2021), Lemna minor performs best in aquaponics at short hydraulic retention time and high flow rate, unlike substrate-rooting plants, Planting density in duckweed aquaponics trades off biomass production against crowding-driven frond mortality, Duckweed retains a smaller share of system nitrogen and phosphorus than fish, but is comparatively efficient among plant biofilter species.

Metadata note (not a severity-tagged contradiction): the PDF’s own header banner reads “Aquaculture Research. 2021;00:1-15 | © 2021” (early-view/online-first pagination), while zotero-export.csv and Crossref give the final issue assignment as volume 53, issue 3, pages 974-988, dated February 2022. This is normal early-access-to-issue publishing behaviour, not a paper self-contradiction; per CLAUDE.md, the Zotero export’s metadata (2022, vol. 53(3), pp. 974-988) is used throughout as the more reliable source.

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Source: Camargo‐Castellanos et al. - 2022 - System management of Lemna minor in aquapon.pdf

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Data Tables

Structured data extracted from this paper into the vault's trials.csv / plant_measurements.csv datasets. Fields the paper didn't report are omitted. Download the full datasets (measurements).

Trial Parameters

camargocastellanosSystemManagementLemna2022-T1

Fish

Field	Value
Fish	Nile tilapia (Oreochromis niloticus)
Fish size initial	281.35 +/- 68.35
Fish survival rate	100%
Fish trial duration (days)	9

Water

Field	Value
Water recycle	166.67
Aq pH	7.66 +/- 0.10
Dissolved Oxigen	5.57 +/- 0.47
EC	1.79 +/- 0.12
Water temperature	24.20 +/- 0.72
TAN / NH4-N	0.025 +/- 0.014

Plant

Field	Value
Plant	Lemna minor (duckweed)
Details	HRT screening trial; six HRT levels tested (15,30,45,60,75,90 min, n=3 HBs each); this row represents the 30-min HRT treatment, identified by the authors as giving the highest biomass production, growth and plant dissemination among the six levels (p.5, p.9). Harvest triggered when any HB reached >90% canopy cover; trial lasted 9 days.
Plant Category	Floating aquatic macrophyte (duckweed) (p.2)
Days Plant after transplant	9

System & Setup

Field	Value
System type	Open-water hydroponic bed (HB), duckweed floating freely on surface, no raft/substrate (p.2-3)
Media Details	NA (no raft or growing medium; L. minor floats freely on the HB water surface, p.2-3)
Air supplement	Y (Compressor BOYU ACQ-009, continuous air injection into the pond, 60 L/min (p.2))
Climate control	Y (Greenhouse-housed system, no setpoints given (p.2))
Equipment	Submersible pump BOYU DJ4P-10000 ECO (10,000 L/h); air compressor BOYU ACQ-009 (60 L/min); Velab VE-5000 digital scale; CANOPEO app (Univ. of Oklahoma) for canopy-cover image analysis (p.2-3)
Control Parameters	HRT (V/Q, min) as the manipulated variable across 6 levels (15/30/45/60/75/90); EC threshold of 1.4 mS/cm3 used to time planting (p.3)
Combination	Nile tilapia (O. niloticus) + Lemna minor (duckweed), single coupled recirculating aquaponic loop; no hydroponic-only control arm in this paper

Site

Field	Value
Region	North America
Country	Mexico
Lat	20.7429
Long	-101.3308

Results & Statistics

Field	Value
Measured Unit	g m-2 (FM, DM, OM in DM, CP in DM) and % (plant dissemination) - reported only in bar/line charts (Fig 3-5), no printed trial-mean values in text or table for Experiment 1
Statistic Details	One-way ANOVA; Cochran test (homogeneity/normality); Tukey’s test, p<0.01 (p.4-5)
Statistically analysed	Y
Replicates (n)	3

Experimental Remarks: TRIAL DEFINITION: T1 = Experiment 1 (hydraulic retention time screening), represented here by the 30-min HRT treatment, the level the authors identify as giving the highest biomass production, growth (RGR) and plant dissemination among the 6 HRT levels tested (15,30,45,60,75,90 min; n=3 HBs/level; p.5,9). The other 5 HRT levels are not given separate rows because their only quantitative outcomes are bar-chart values in Figure 3 and a line graph in Figure 5, with no printed trial-mean numbers in text or table anywhere in the paper (per the ‘never read a value off a figure’ rule these values cannot be entered in any cell); only the qualitative ranking is stated in running text. No hydroponic-only control exists for this or any trial in this paper (paired HYD columns = NA throughout). | NO COLUMN: HRT design values (15,30,45,60,75,90 min) and the HRT formula (HRT=V/Q, V=0.1 m3 per HB) have no dedicated schema column; Water recycle above uses the whole-system pump rating, not the per-HB flow implied by 30-min HRT (Q=V/HRT=0.2 m3/h for this specific treatment), which the paper never states as a number (computing it would be derivation). | NO COLUMN: Figure 4 prints explicit ‘Canopy Cover’ data-labels on the harvest-day images for each HRT level (15/30/45/60/75/90 min: 91.16/94.79/78.49/72.03/75.35/77.51 %), but these appear to be single-image/single-day snapshots (the caption does not state they are n=3 trial means; Figure 5’s actual mean+/-SE time series carries no printed final values). Given the ambiguity over whether these are trial means, they are recorded here for reference only, not entered as a schema cell. | Individual system compartment volumes given but no aggregate stated: pond VEf=3.6 m3, settler-clarifier=0.4 m3, biofilter=1.0 m3, 18 HB x 0.1 m3=1.8 m3 (p.2); summing would be derivation, so Water volume in the system left NR. | UNIT CONVERSION ONLY: pump BOYU DJ4P-10000 ECO rated 10,000 L/h -> 166.67 L/min (Water recycle cell); site coordinates 20 deg 44’ 34.42” N, 101 deg 19’ 50.7” W -> decimal 20.7429, -101.3308 (both minutes/seconds within valid range, straightforward conversion, not a BLOCK case). | [unclear] Fish survival rate: paper states ‘no mortality’ for Experiments 1 and 2 (p.5) but never gives a numeric survival %; recorded as 100% as the direct logical equivalent of ‘no mortality’, not a derivation from other data. | [unclear] Protein/N/P/K/% of body weight/Feed routine/Feed regime: the diet description (35% CP, 7% ether extract, 5% crude fibre, 13% ash, 25.8% NFE, fed at 3% body weight/day) is grammatically attached only to the sentence introducing Experiment 2’s fish cohort (p.3: ‘In experiment 2, 200 individuals… were used, which were fed with a rate of 3% per day, with a balanced feed…’); Experiment 1’s fish (215 individuals) are introduced in the preceding sentence with no feed description attached. Left NR rather than assumed identical. | [unclear] It is unclear how the ‘crude protein (CP in DM) = DM * %CP’ study-variable formula (section 2.1.3d) was evaluated for Experiments 1-2, since the chemical/bromatological analysis method (section 2.2.4, which is what measured %CP) is described only for Experiment 3; Figure 3 nonetheless reports g/m2 CP values for Experiments 1-2. Source of the %CP figure used for Exp 1-2 is not stated. | WARN-MINOR RGR unit/basis: Table 1’s RGR column is headed ‘RGR / m2 day-1’, but Methods (2.1.3e) defines RGR (day-1) = ln(DM produced g m2)/days, i.e. a per-day rate, not per-m2-per-day; the ‘m2’ in the table header appears to be a layout artefact bleeding over from the adjacent column rather than a distinct unit. No numeric impact - values transcribed as printed (applies to T3-T5, not to this figure-only trial). | WARN-CHECK RGR reported under two different bases with no dedicated schema column (see T3-T5 for the actual numbers; flagged once here as it is a duckweed-wide issue): Table 1 gives per-planting-area RGR while Table 2 gives whole-system-total RGR; both use the same formula but different input bases and the paper never states which is ‘the’ RGR for cross-paper comparison. This is the duckweed relative-growth-rate ambiguity flagged as a known risk in the extraction brief; neither has a home in this schema (no RGR column exists). | NOT DERIVED, left NR: Initial Stock density (215 fish, pond VEf=3.6 m3 - would require computing kg/m3); Fish weight gain, FCR, SGR, Total Feed (kg), Fish biomass created (kg) (none of these values or their full input sets are stated for Experiment 1); Plants/m2 (Lemna is planted by mass, g/m2, not a plant count); Water volume in the system (see compartment note above).

camargocastellanosSystemManagementLemna2022-T2

Fish

Field	Value
Fish	Nile tilapia (Oreochromis niloticus)
Protein	35
% of body weight	3
Fish size initial	290.76 +/- 70.57
Feed regime	Balanced feed specific to species: 35% crude protein, 7% ether extract, 5% crude fibre, 13% ash, 25.8% nitrogen-free extract; fed at 3% body weight/day (p.3)
Fish survival rate	100%
Fish trial duration (days)	7

Water

Field	Value
Water recycle	166.67
Aq pH	7.67 +/- 0.11
Dissolved Oxigen	5.64 +/- 0.49
EC	1.83 +/- 0.11
Water temperature	24.75 +/- 0.49
TAN / NH4-N	0.026 +/- 0.005

Plant

Field	Value
Plant	Lemna minor (duckweed)
Details	Planting density (PD) screening trial; six PD levels tested (50,100,150,200,250,300 g/m2 FM, n=3 HBs each), using the 30-min HRT identified as best in Experiment 1. This row represents the 300 g/m2 treatment, identified by the authors as giving the highest biomass production, growth (RGR) and plant dissemination among the 6 PD levels (p.5,9). Harvest triggered at >90% canopy cover in any HB; trial lasted 7 days.
Plant Category	Floating aquatic macrophyte (duckweed) (p.2)
Days Plant after transplant	7

System & Setup

Field	Value
System type	Open-water hydroponic bed (HB), duckweed floating freely on surface, no raft/substrate (p.2-3)
Media Details	NA (no raft or growing medium; L. minor floats freely on the HB water surface, p.2-3)
Air supplement	Y (Compressor BOYU ACQ-009, continuous air injection into the pond, 60 L/min (p.2))
Climate control	Y (Greenhouse-housed system, no setpoints given (p.2))
Equipment	Submersible pump BOYU DJ4P-10000 ECO (10,000 L/h); air compressor BOYU ACQ-009 (60 L/min); Velab VE-5000 digital scale; CANOPEO app (Univ. of Oklahoma) for canopy-cover image analysis (p.2-3)
Control Parameters	Planting density (PD, g/m2 FM at stocking) as the manipulated variable across 6 levels (50/100/150/200/250/300); HRT fixed at 30 min (best from Experiment 1) (p.3)
Combination	Nile tilapia (O. niloticus) + Lemna minor (duckweed), single coupled recirculating aquaponic loop; no hydroponic-only control arm in this paper

Site

Field	Value
Region	North America
Country	Mexico
Lat	20.7429
Long	-101.3308

Results & Statistics

Field	Value
Measured Unit	g m-2 (FM, DM, OM in DM, CP in DM) and % (plant dissemination) - reported only in bar/line charts (Fig 3-5), no printed trial-mean values in text or table for Experiment 2
Statistic Details	One-way ANOVA; Cochran test (homogeneity/normality); Tukey’s test, p<0.01 (p.4-5)
Statistically analysed	Y
Replicates (n)	3

Experimental Remarks: TRIAL DEFINITION: T2 = Experiment 2 (planting density screening), represented here by the 300 g/m2 treatment, the level the authors identify as giving the highest biomass production, growth (RGR) and plant dissemination among the 6 PD levels tested (50,100,150,200,250,300 g/m2; n=3 HBs/level; p.5,9), run at the 30-min HRT established in Experiment 1. The other 5 PD levels are not given separate rows for the same reason as Experiment 1 (T1): their only quantitative outcomes are bar-chart values in Figure 3 and a line graph in Figure 5, with no printed trial-mean numbers anywhere in text or table. No hydroponic-only control exists in this paper. | NO COLUMN: PD design values (50,100,150,200,250,300 g/m2 as planted biomass) have no dedicated schema column (Plants/m2 is a per-plant count column and does not fit Lemna’s areal-biomass stocking metric - see Plant Category). | NO COLUMN: Figure 4 prints explicit ‘Canopy Cover’ data-labels on the harvest-day images for each PD level (50/100/150/200/250/300 g/m2: 41.88/61.14/61.95/83.02/91.82/99.90 %), single-image/single-day snapshots not confirmed to be n=3 trial means (see T1 remark for the same caveat on Figure 4/5); recorded here for reference only, not entered as a schema cell. | [unclear] Whether the EC=1.4 mS/cm3 planting threshold stated for Experiment 1 (p.3) also applied to Experiment 2’s varying-density plantings; not restated in the PD-specific description (section 2.1.3), so Control Parameters omits an EC threshold for this trial rather than assuming it. | UNIT CONVERSION ONLY: pump BOYU DJ4P-10000 ECO rated 10,000 L/h -> 166.67 L/min (Water recycle cell, same shared system as T1); site coordinates 20 deg 44’ 34.42” N, 101 deg 19’ 50.7” W -> decimal 20.7429, -101.3308. | Regarding the fish, two organisms with tail fin fraying were observed in Experiment 2 specifically (p.5); no other welfare issues, no mortality, no disease signs reported for either Experiment 1 or 2. | NOT DERIVED, left NR: Initial Stock density (200 fish, pond VEf=3.6 m3); Fish size final, Fish weight gain, FCR, SGR, Total Feed (kg), Fish biomass created (kg) (feed rate 3%/day and duration 7 days are both stated, but no total feed figure is printed - computing kg would be derivation); Plants/m2 (density is by mass, g/m2, not count); Water volume in the system (see T1 compartment note, same system).

camargocastellanosSystemManagementLemna2022-T3

Fish

Field	Value
Fish	Nile tilapia (Oreochromis niloticus)
SGR	1.43 +/- 0.05
Protein	35
N	6.08
P	1.30
% of body weight	2.5
Fish size initial	136.95 +/- 4.97
Feed regime	350 g/pond/day (2.5% feed rate); feed composition stated as ‘like the previous experiments’ (p.4) - i.e. presumably the same diet described for Experiment 2 (35% CP, 7% ether extract, 5% crude fibre, 13% ash, 25.8% NFE), not independently restated for Experiment 3. Feed assayed at 88.0% dry matter, 6.08% N and 1.30% P in DM (Table 4 footnote a).
Total Feed (kg)	3.080
Fish survival rate	100%
Fish trial duration (days)	10

Water

Field	Value
Water recycle	46.67
Water volume in the system	2089.4
Aq pH	7.66 +/- 0.15
Dissolved Oxigen	5.69 +/- 0.30
EC	1.59 +/- 0.09
Water temperature	24.20 +/- 0.82
TAN / NH4-N	0.023 +/- 0.005

Plant

Field	Value
Plant	Lemna minor (duckweed)
Details	Planting-area mass-balance trial, 5 m2 of planting area (of 3 levels tested: 5/6/7 m2, n=3 independent aquaponic systems per level), using HRT=30 min and PD=300 g/m2 carried forward as best from Experiments 1-2. Trial lasted 10 days.
Plant Category	Floating aquatic macrophyte (duckweed) (p.2)
Days Plant after transplant	10
Plant dry matter	7.75

System & Setup

Field	Value
System type	Open-water hydroponic bed (HB), duckweed floating freely on surface, no raft/substrate (p.4)
Media Details	NA (no raft or growing medium; L. minor floats freely on the HB water surface, p.4)
Air supplement	Y (Compressor BOYU ACQ-009, continuous air injection shared across every three tanks, 60 L/min (p.4))
Climate control	Y (Greenhouse-housed system, no setpoints given (p.4))
Equipment	Submersible pump RESUN SP6000 (2,800 L/h); air compressor BOYU ACQ-009 (60 L/min, shared per 3 tanks); Velab VE-5000 digital scale; CANOPEO app; YSI Professional Plus multiparameter probe (temp, DO, EC, NH4+, pH); IKA Calorimeter System C 2000 Basic (bomb calorimeter, gross energy); Kjeldahl method (N, Kirk 1950); AOAC methods 1995/1997/2000 (ash, P, Ca); ANKOM methods 2018 a/b/c (NDF, ADF, lignin); LabVIEW NXG 5.0 (2020) for system volume/flow modelling (p.4)
Control Parameters	Planting area (5 m2, i.e. 5 of the HBs stocked) as the manipulated variable across 3 levels (5/6/7 m2, n=3 systems each); HRT fixed at 30 min and PD fixed at 300 g/m2 (best levels from Experiments 1-2); EC threshold of 1.5 mS/cm3 used to time planting (p.4)
Combination	Nile tilapia (O. niloticus) + Lemna minor (duckweed), single coupled recirculating aquaponic loop with full N/P/DM mass-balance accounting; no hydroponic-only control arm

Site

Field	Value
Region	North America
Country	Mexico

Results & Statistics

Field	Value
Measured Unit	g m-2 (fresh matter, dry matter, organic matter, crude protein, hemicellulose, cellulose - Table 1/2); day-1 (RGR - Table 1/2, two different bases, see remarks); % (dry matter, crude protein, NDF, ADF, lignin, ash, Ca, P of plant tissue - Section 3.2, and plant dissemination - Table 2); cal/g (gross energy)
Statistic Details	One-way ANOVA; Bartlett test (homogeneity/normality); Bonferroni test for mean comparisons (p.5)
Statistically analysed	Y
Replicates (n)	3
AP	609.73

Experimental Remarks: TRIAL DEFINITION: T3 = Experiment 3, 5 m2 planting area treatment (of 3 levels tested: 5/6/7 m2, n=3 independent aquaponic systems per level), using HRT=30 min and PD=300 g/m2 carried forward as the best levels from Experiments 1-2 (T1, T2). Paired control: none (no hydroponic-only arm in this paper); compared instead against the other two planting-area treatments within Experiment 3. | NO COLUMN (Table 1, per-m2 production, means+/-SE, n=3): dry matter 47.25 +/- 1.14 g/m2; organic matter 37.91 +/- 0.91 g/m2 in DM; crude protein 14.17 +/- 0.32 g/m2 in DM; hemicellulose 8.63 +/- 0.20 g/m2 in DM; cellulose 4.63 +/- 0.11 g/m2 in DM; RGR 0.385 +/- 0.002 (letter a) day-1 (Table 1’s own header prints ‘m2 day-1’, likely a layout artefact - see WARN-MINOR below). | NO COLUMN (Table 2, whole-system totals, n=3): fresh matter 3048.67 +/- 160.46 g; dry matter 236.27 +/- 12.43 g; organic matter 189.56 +/- 9.97 g; crude protein 70.85 +/- 3.72 g; hemicellulose 43.19 +/- 2.27 g; cellulose 23.18 +/- 1.22 g; RGR (whole-system basis) 0.546 +/- 0.005 day-1; plant dissemination 89.6 +/- 1.31% (letter a). | NO COLUMN (Section 3.2 bromatological analysis, reported once for the whole Experiment 3, not broken down by area - see [unclear] below): NDF 34.16%, ADF 15.88%, lignin 6.07%, ash 19.77%, Ca 2.02%, P 1.1%, gross energy 3490 cal/g, crude protein 30.0% (all also recorded in plant_measurements.csv). | NO COLUMN (Table 3, DM mass balance, mean+/-SD, n=3, % of 3.080 kg DM feed input): fish incorporated 0.502 +/- 0.21 kg (16.32%); plants removal 0.236 +/- 0.02 kg (7.67%, matches this row’s AP fresh/dry-matter production); WPR/sludge 1.360 +/- 0.06 kg (44.17%); water (calculated by difference, per paper) 0.980 +/- 0.02 kg (31.84%). | NO COLUMN (Table 4, N and P mass balance, mean+/-SD, n=3, % of 18.73 g N/d and 3.39 g P/d feed input): fish N 4.27 +/- 0.18 g/d (22.82%), fish P 1.51 +/- 0.07 g/d (44.67%); plants N 1.13 +/- 0.10 g/d (6.06%), plants P 0.26 +/- 0.02 g/d (7.67%); sludge N 4.45 +/- 0.22 g/d (23.74%), sludge P 0.82 +/- 0.04 g/d (24.09%); water N 4.08 g/d (21.79%, no SD given in paper), water P 0.033 g/d (0.99%, no SD given in paper); others/not-accounted N 4.79 +/- 0.07 g/d (25.59%), others P 0.77 +/- 0.05 g/d (22.58%). | [unclear] Section 3.2’s bromatological values (DM 7.75%, CP 30.0%, NDF/ADF/lignin/ash/Ca/P/GE) are stated once for ‘the plant material’ with no breakdown by planting-area treatment (5/6/7 m2); applied identically to T3, T4 and T5 in plant_measurements.csv with a note flagging the shared, non-treatment-specific value. | [unclear] Site coordinates/exact facility for Experiment 3 not restated in section 2.2 (unlike Experiments 1-2, which give explicit GPS at Univ. Guanajuato’s Aquaculture Laboratory, Irapuato); authors’ affiliations span both Irapuato (Univ. Guanajuato) and Villahermosa (DACBIOL-UJAT) institutions, so the specific site cannot be confirmed - Lat/Long left NR; Region/Country recorded as Mexico/North America since both candidate institutions are Mexican. | WARN-MINOR feed N-to-protein cross-check: Table 4’s feed N (6.08% DM) x 6.25 (standard Kjeldahl factor) = 38.0% CP, vs the diet’s nominal label of ‘35% crude protein’ given in Experiment 2’s feed description (p.3, section 2.1.2) and presumably reused here per the ‘management of the fish was like the previous experiments’ statement (p.4, section 2.2.2). ~8.6% relative gap, plausibly a feed-lot/assay difference or a different Kjeldahl N-to-protein factor for this diet; not flagged as a cell conflict since the two figures come from two different measurements (manufacturer/nominal label vs directly-assayed feed N%). | WARN-MINOR fish stocking arithmetic check: 100 fish x 136.95 g mean weight = 13,695 g = 13.695 kg, vs the stated total pond biomass of 13.89 +/- 0.50 kg (~1.4% higher than the recomputed figure, within the paper’s own stated 3.6% CV across the 9 ponds) - both figures plausibly correct as different aggregations (grand mean of 900 individual fish across 9 ponds vs mean of 9 pond totals); not a cell conflict, both are direct-report figures, not entered as an inconsistency. | WARN-MINOR abstract rounding: the Abstract/Conclusions state ‘between 7% and 8% of the nutrients (input in dry matter, N and P) are retained by L. minor’, but the more precise in-text figure (Section 4.3, p.11) gives ‘retention between 6%-7% of N and 7%-9% of P’, and this row’s own Table 3/4 per-treatment values (DM 7.67%, N 6.06%, P 7.67%) show N below the abstract’s stated 7-8% floor. The precise Table 3/4 values are used in every cell above regardless of the abstract’s rounded summary claim, so no cell is affected. | NOT DERIVED, left NR: Initial Stock density (13.89 kg total pond biomass and VEf=1 m3 are both stated, so 13.89 kg/m3 is trivially computable, but not itself printed in the paper - both inputs given here for downstream computation if desired); Fish biomass created (kg), Fish weight gain (SGR of 1.43 +/- 0.05% animal/day is given, but no final pond weight or gain figure is printed); Plant fresh weight/Plant height/Leaf count per-plant metrics (Lemna has no discrete per-plant fresh weight, height, or leaf/frond count reported or applicable - see next line); Plants/m2 (density is reported by mass, g/m2, not plant count). Plant height and Leaf count recorded NA: L. minor has no stem separate from the leaves (fused into a single ‘frond’ structure) and was not analysed for discrete leaf/frond counts anywhere in the paper (p.2).

camargocastellanosSystemManagementLemna2022-T4

Fish

Field	Value
Fish	Nile tilapia (Oreochromis niloticus)
SGR	1.43 +/- 0.05
Protein	35
N	6.08
P	1.30
% of body weight	2.5
Fish size initial	136.95 +/- 4.97
Feed regime	350 g/pond/day (2.5% feed rate); feed composition stated as ‘like the previous experiments’ (p.4) - i.e. presumably the same diet described for Experiment 2 (35% CP, 7% ether extract, 5% crude fibre, 13% ash, 25.8% NFE), not independently restated for Experiment 3. Feed assayed at 88.0% dry matter, 6.08% N and 1.30% P in DM (Table 4 footnote a).
Total Feed (kg)	3.080
Fish survival rate	100%
Fish trial duration (days)	10

Water

Field	Value
Water recycle	46.67
Water volume in the system	2202.4
Aq pH	7.66 +/- 0.15
Dissolved Oxigen	5.69 +/- 0.30
EC	1.59 +/- 0.09
Water temperature	24.20 +/- 0.82
TAN / NH4-N	0.023 +/- 0.005

Plant

Field	Value
Plant	Lemna minor (duckweed)
Details	Planting-area mass-balance trial, 6 m2 of planting area (of 3 levels tested: 5/6/7 m2, n=3 independent aquaponic systems per level), using HRT=30 min and PD=300 g/m2 carried forward as best from Experiments 1-2. Trial lasted 10 days.
Plant Category	Floating aquatic macrophyte (duckweed) (p.2)
Days Plant after transplant	10
Plant dry matter	7.75

System & Setup

Field	Value
System type	Open-water hydroponic bed (HB), duckweed floating freely on surface, no raft/substrate (p.4)
Media Details	NA (no raft or growing medium; L. minor floats freely on the HB water surface, p.4)
Air supplement	Y (Compressor BOYU ACQ-009, continuous air injection shared across every three tanks, 60 L/min (p.4))
Climate control	Y (Greenhouse-housed system, no setpoints given (p.4))
Equipment	Submersible pump RESUN SP6000 (2,800 L/h); air compressor BOYU ACQ-009 (60 L/min, shared per 3 tanks); Velab VE-5000 digital scale; CANOPEO app; YSI Professional Plus multiparameter probe (temp, DO, EC, NH4+, pH); IKA Calorimeter System C 2000 Basic (bomb calorimeter, gross energy); Kjeldahl method (N, Kirk 1950); AOAC methods 1995/1997/2000 (ash, P, Ca); ANKOM methods 2018 a/b/c (NDF, ADF, lignin); LabVIEW NXG 5.0 (2020) for system volume/flow modelling (p.4)
Control Parameters	Planting area (6 m2, i.e. 6 of the HBs stocked) as the manipulated variable across 3 levels (5/6/7 m2, n=3 systems each); HRT fixed at 30 min and PD fixed at 300 g/m2 (best levels from Experiments 1-2); EC threshold of 1.5 mS/cm3 used to time planting (p.4)
Combination	Nile tilapia (O. niloticus) + Lemna minor (duckweed), single coupled recirculating aquaponic loop with full N/P/DM mass-balance accounting; no hydroponic-only control arm

Site

Field	Value
Region	North America
Country	Mexico

Results & Statistics

Field	Value
Measured Unit	g m-2 (fresh matter, dry matter, organic matter, crude protein, hemicellulose, cellulose - Table 1/2); day-1 (RGR - Table 1/2, two different bases, see remarks); % (dry matter, crude protein, NDF, ADF, lignin, ash, Ca, P of plant tissue - Section 3.2, and plant dissemination - Table 2); cal/g (gross energy)
Statistic Details	One-way ANOVA; Bartlett test (homogeneity/normality); Bonferroni test for mean comparisons (p.5)
Statistically analysed	Y
Replicates (n)	3
AP	568.01

Experimental Remarks: TRIAL DEFINITION: T4 = Experiment 3, 6 m2 planting area treatment (of 3 levels tested: 5/6/7 m2, n=3 independent aquaponic systems per level), using HRT=30 min and PD=300 g/m2 carried forward as the best levels from Experiments 1-2 (T1, T2). Paired control: none (no hydroponic-only arm in this paper); compared instead against the other two planting-area treatments within Experiment 3. | NO COLUMN (Table 1, per-m2 production, means+/-SE, n=3): dry matter 44.02 +/- 0.98 g/m2; organic matter 35.31 +/- 0.78 g/m2 in DM; crude protein 13.20 +/- 0.29 g/m2 in DM; hemicellulose 8.04 +/- 0.17 g/m2 in DM; cellulose 4.31 +/- 0.09 g/m2 in DM; RGR 0.378 +/- 0.002 (letter a) day-1 (Table 1’s own header prints ‘m2 day-1’, likely a layout artefact - see WARN-MINOR below). | NO COLUMN (Table 2, whole-system totals, n=3): fresh matter 3408.10 +/- 159.07 g; dry matter 264.12 +/- 12.32 g; organic matter 211.91 +/- 9.89 g; crude protein 79.21 +/- 3.69 g; hemicellulose 48.28 +/- 2.25 g; cellulose 25.91 +/- 1.20 g; RGR (whole-system basis) 0.557 +/- 0.004 day-1; plant dissemination 69.82 +/- 3.23% (letter b). | NO COLUMN (Section 3.2 bromatological analysis, reported once for the whole Experiment 3, not broken down by area - see [unclear] below): NDF 34.16%, ADF 15.88%, lignin 6.07%, ash 19.77%, Ca 2.02%, P 1.1%, gross energy 3490 cal/g, crude protein 30.0% (all also recorded in plant_measurements.csv). | NO COLUMN (Table 3, DM mass balance, mean+/-SD, n=3, % of 3.080 kg DM feed input): fish incorporated 0.521 +/- 0.16 kg (16.94%); plants removal 0.264 +/- 0.02 kg (8.58%, matches this row’s AP fresh/dry-matter production); WPR/sludge 1.300 +/- 0.04 kg (42.21%); water (calculated by difference, per paper) 0.993 +/- 0.02 kg (32.27%). | NO COLUMN (Table 4, N and P mass balance, mean+/-SD, n=3, % of 18.73 g N/d and 3.39 g P/d feed input): fish N 4.44 +/- 0.14 g/d (23.69%), fish P 1.57 +/- 0.05 g/d (46.36%); plants N 1.27 +/- 0.10 g/d (6.77%), plants P 0.29 +/- 0.02 g/d (8.58%); sludge N 4.25 +/- 0.16 g/d (22.68%), sludge P 0.78 +/- 0.03 g/d (23.02%); water N 4.30 g/d (22.97%, no SD given in paper), water P 0.035 g/d (1.04%, no SD given in paper); others/not-accounted N 4.47 +/- 0.09 g/d (23.89%), others P 0.71 +/- 0.04 g/d (21.00%). | [unclear] Section 3.2’s bromatological values (DM 7.75%, CP 30.0%, NDF/ADF/lignin/ash/Ca/P/GE) are stated once for ‘the plant material’ with no breakdown by planting-area treatment (5/6/7 m2); applied identically to T3, T4 and T5 in plant_measurements.csv with a note flagging the shared, non-treatment-specific value. | [unclear] Site coordinates/exact facility for Experiment 3 not restated in section 2.2 (unlike Experiments 1-2, which give explicit GPS at Univ. Guanajuato’s Aquaculture Laboratory, Irapuato); authors’ affiliations span both Irapuato (Univ. Guanajuato) and Villahermosa (DACBIOL-UJAT) institutions, so the specific site cannot be confirmed - Lat/Long left NR; Region/Country recorded as Mexico/North America since both candidate institutions are Mexican. | WARN-MINOR feed N-to-protein cross-check: Table 4’s feed N (6.08% DM) x 6.25 (standard Kjeldahl factor) = 38.0% CP, vs the diet’s nominal label of ‘35% crude protein’ given in Experiment 2’s feed description (p.3, section 2.1.2) and presumably reused here per the ‘management of the fish was like the previous experiments’ statement (p.4, section 2.2.2). ~8.6% relative gap, plausibly a feed-lot/assay difference or a different Kjeldahl N-to-protein factor for this diet; not flagged as a cell conflict since the two figures come from two different measurements (manufacturer/nominal label vs directly-assayed feed N%). | WARN-MINOR fish stocking arithmetic check: 100 fish x 136.95 g mean weight = 13,695 g = 13.695 kg, vs the stated total pond biomass of 13.89 +/- 0.50 kg (~1.4% higher than the recomputed figure, within the paper’s own stated 3.6% CV across the 9 ponds) - both figures plausibly correct as different aggregations (grand mean of 900 individual fish across 9 ponds vs mean of 9 pond totals); not a cell conflict, both are direct-report figures, not entered as an inconsistency. | WARN-MINOR abstract rounding: the Abstract/Conclusions state ‘between 7% and 8% of the nutrients (input in dry matter, N and P) are retained by L. minor’, but the more precise in-text figure (Section 4.3, p.11) gives ‘retention between 6%-7% of N and 7%-9% of P’, and this row’s own Table 3/4 per-treatment values (DM 8.58%, N 6.77%, P 8.58%) show N below the abstract’s stated 7-8% floor. The precise Table 3/4 values are used in every cell above regardless of the abstract’s rounded summary claim, so no cell is affected. | NOT DERIVED, left NR: Initial Stock density (13.89 kg total pond biomass and VEf=1 m3 are both stated, so 13.89 kg/m3 is trivially computable, but not itself printed in the paper - both inputs given here for downstream computation if desired); Fish biomass created (kg), Fish weight gain (SGR of 1.43 +/- 0.05% animal/day is given, but no final pond weight or gain figure is printed); Plant fresh weight/Plant height/Leaf count per-plant metrics (Lemna has no discrete per-plant fresh weight, height, or leaf/frond count reported or applicable - see next line); Plants/m2 (density is reported by mass, g/m2, not plant count). Plant height and Leaf count recorded NA: L. minor has no stem separate from the leaves (fused into a single ‘frond’ structure) and was not analysed for discrete leaf/frond counts anywhere in the paper (p.2).

camargocastellanosSystemManagementLemna2022-T5

Fish

Field	Value
Fish	Nile tilapia (Oreochromis niloticus)
SGR	1.43 +/- 0.05
Protein	35
N	6.08
P	1.30
% of body weight	2.5
Fish size initial	136.95 +/- 4.97
Feed regime	350 g/pond/day (2.5% feed rate); feed composition stated as ‘like the previous experiments’ (p.4) - i.e. presumably the same diet described for Experiment 2 (35% CP, 7% ether extract, 5% crude fibre, 13% ash, 25.8% NFE), not independently restated for Experiment 3. Feed assayed at 88.0% dry matter, 6.08% N and 1.30% P in DM (Table 4 footnote a).
Total Feed (kg)	3.080
Fish survival rate	100%
Fish trial duration (days)	10

Water

Field	Value
Water recycle	46.67
Water volume in the system	2314.8
Aq pH	7.66 +/- 0.15
Dissolved Oxigen	5.69 +/- 0.30
EC	1.59 +/- 0.09
Water temperature	24.20 +/- 0.82
TAN / NH4-N	0.023 +/- 0.005

Plant

Field	Value
Plant	Lemna minor (duckweed)
Details	Planting-area mass-balance trial, 7 m2 of planting area (of 3 levels tested: 5/6/7 m2, n=3 independent aquaponic systems per level), using HRT=30 min and PD=300 g/m2 carried forward as best from Experiments 1-2. Trial lasted 10 days.
Plant Category	Floating aquatic macrophyte (duckweed) (p.2)
Days Plant after transplant	10
Plant dry matter	7.75

System & Setup

Field	Value
System type	Open-water hydroponic bed (HB), duckweed floating freely on surface, no raft/substrate (p.4)
Media Details	NA (no raft or growing medium; L. minor floats freely on the HB water surface, p.4)
Air supplement	Y (Compressor BOYU ACQ-009, continuous air injection shared across every three tanks, 60 L/min (p.4))
Climate control	Y (Greenhouse-housed system, no setpoints given (p.4))
Equipment	Submersible pump RESUN SP6000 (2,800 L/h); air compressor BOYU ACQ-009 (60 L/min, shared per 3 tanks); Velab VE-5000 digital scale; CANOPEO app; YSI Professional Plus multiparameter probe (temp, DO, EC, NH4+, pH); IKA Calorimeter System C 2000 Basic (bomb calorimeter, gross energy); Kjeldahl method (N, Kirk 1950); AOAC methods 1995/1997/2000 (ash, P, Ca); ANKOM methods 2018 a/b/c (NDF, ADF, lignin); LabVIEW NXG 5.0 (2020) for system volume/flow modelling (p.4)
Control Parameters	Planting area (7 m2, i.e. 7 of the HBs stocked) as the manipulated variable across 3 levels (5/6/7 m2, n=3 systems each); HRT fixed at 30 min and PD fixed at 300 g/m2 (best levels from Experiments 1-2); EC threshold of 1.5 mS/cm3 used to time planting (p.4)
Combination	Nile tilapia (O. niloticus) + Lemna minor (duckweed), single coupled recirculating aquaponic loop with full N/P/DM mass-balance accounting; no hydroponic-only control arm

Site

Field	Value
Region	North America
Country	Mexico

Results & Statistics

Field	Value
Measured Unit	g m-2 (fresh matter, dry matter, organic matter, crude protein, hemicellulose, cellulose - Table 1/2); day-1 (RGR - Table 1/2, two different bases, see remarks); % (dry matter, crude protein, NDF, ADF, lignin, ash, Ca, P of plant tissue - Section 3.2, and plant dissemination - Table 2); cal/g (gross energy)
Statistic Details	One-way ANOVA; Bartlett test (homogeneity/normality); Bonferroni test for mean comparisons (p.5)
Statistically analysed	Y
Replicates (n)	3
AP	477.97

Experimental Remarks: TRIAL DEFINITION: T5 = Experiment 3, 7 m2 planting area treatment (of 3 levels tested: 5/6/7 m2, n=3 independent aquaponic systems per level), using HRT=30 min and PD=300 g/m2 carried forward as the best levels from Experiments 1-2 (T1, T2). Paired control: none (no hydroponic-only arm in this paper); compared instead against the other two planting-area treatments within Experiment 3. | NO COLUMN (Table 1, per-m2 production, means+/-SE, n=3): dry matter 37.04 +/- 0.49 g/m2; organic matter 29.71 +/- 0.39 g/m2 in DM; crude protein 11.10 +/- 0.14 g/m2 in DM; hemicellulose 6.77 +/- 0.08 g/m2 in DM; cellulose 3.63 +/- 0.04 g/m2 in DM; RGR 0.361 +/- 0.001 (letter b) day-1 (Table 1’s own header prints ‘m2 day-1’, likely a layout artefact - see WARN-MINOR below). | NO COLUMN (Table 2, whole-system totals, n=3): fresh matter 3345.80 +/- 58.71 g; dry matter 259.29 +/- 4.55 g; organic matter 208.03 +/- 3.64 g; crude protein 77.76 +/- 1.36 g; hemicellulose 47.39 +/- 0.83 g; cellulose 25.43 +/- 0.44 g; RGR (whole-system basis) 0.555 +/- 0.001 day-1; plant dissemination 46.42 +/- 2.52% (letter c). | NO COLUMN (Section 3.2 bromatological analysis, reported once for the whole Experiment 3, not broken down by area - see [unclear] below): NDF 34.16%, ADF 15.88%, lignin 6.07%, ash 19.77%, Ca 2.02%, P 1.1%, gross energy 3490 cal/g, crude protein 30.0% (all also recorded in plant_measurements.csv). | NO COLUMN (Table 3, DM mass balance, mean+/-SD, n=3, % of 3.080 kg DM feed input): fish incorporated 0.497 +/- 0.11 kg (16.15%); plants removal 0.259 +/- 0.007 kg (8.42%, matches this row’s AP fresh/dry-matter production); WPR/sludge 1.376 +/- 0.03 kg (44.69%); water (calculated by difference, per paper) 0.946 +/- 0.03 kg (30.74%). | NO COLUMN (Table 4, N and P mass balance, mean+/-SD, n=3, % of 18.73 g N/d and 3.39 g P/d feed input): fish N 4.23 +/- 0.51 g/d (22.58%), fish P 1.50 +/- 1.00 g/d (44.19%); plants N 1.24 +/- 0.20 g/d (6.65%), plants P 0.29 +/- 0.26 g/d (8.42%); sludge N 4.50 +/- 0.64 g/d (24.02%), sludge P 0.83 +/- 0.65 g/d (24.37%); water N 4.52 g/d (24.14%, no SD given in paper), water P 0.037 g/d (1.09%, no SD given in paper); others/not-accounted N 4.24 +/- 0.33 g/d (22.62%), others P 0.74 +/- 0.12 g/d (21.92%). | [unclear] Section 3.2’s bromatological values (DM 7.75%, CP 30.0%, NDF/ADF/lignin/ash/Ca/P/GE) are stated once for ‘the plant material’ with no breakdown by planting-area treatment (5/6/7 m2); applied identically to T3, T4 and T5 in plant_measurements.csv with a note flagging the shared, non-treatment-specific value. | [unclear] Site coordinates/exact facility for Experiment 3 not restated in section 2.2 (unlike Experiments 1-2, which give explicit GPS at Univ. Guanajuato’s Aquaculture Laboratory, Irapuato); authors’ affiliations span both Irapuato (Univ. Guanajuato) and Villahermosa (DACBIOL-UJAT) institutions, so the specific site cannot be confirmed - Lat/Long left NR; Region/Country recorded as Mexico/North America since both candidate institutions are Mexican. | WARN-MINOR feed N-to-protein cross-check: Table 4’s feed N (6.08% DM) x 6.25 (standard Kjeldahl factor) = 38.0% CP, vs the diet’s nominal label of ‘35% crude protein’ given in Experiment 2’s feed description (p.3, section 2.1.2) and presumably reused here per the ‘management of the fish was like the previous experiments’ statement (p.4, section 2.2.2). ~8.6% relative gap, plausibly a feed-lot/assay difference or a different Kjeldahl N-to-protein factor for this diet; not flagged as a cell conflict since the two figures come from two different measurements (manufacturer/nominal label vs directly-assayed feed N%). | WARN-MINOR fish stocking arithmetic check: 100 fish x 136.95 g mean weight = 13,695 g = 13.695 kg, vs the stated total pond biomass of 13.89 +/- 0.50 kg (~1.4% higher than the recomputed figure, within the paper’s own stated 3.6% CV across the 9 ponds) - both figures plausibly correct as different aggregations (grand mean of 900 individual fish across 9 ponds vs mean of 9 pond totals); not a cell conflict, both are direct-report figures, not entered as an inconsistency. | WARN-MINOR abstract rounding: the Abstract/Conclusions state ‘between 7% and 8% of the nutrients (input in dry matter, N and P) are retained by L. minor’, but the more precise in-text figure (Section 4.3, p.11) gives ‘retention between 6%-7% of N and 7%-9% of P’, and this row’s own Table 3/4 per-treatment values (DM 8.42%, N 6.65%, P 8.42%) show N below the abstract’s stated 7-8% floor. The precise Table 3/4 values are used in every cell above regardless of the abstract’s rounded summary claim, so no cell is affected. | NOT DERIVED, left NR: Initial Stock density (13.89 kg total pond biomass and VEf=1 m3 are both stated, so 13.89 kg/m3 is trivially computable, but not itself printed in the paper - both inputs given here for downstream computation if desired); Fish biomass created (kg), Fish weight gain (SGR of 1.43 +/- 0.05% animal/day is given, but no final pond weight or gain figure is printed); Plant fresh weight/Plant height/Leaf count per-plant metrics (Lemna has no discrete per-plant fresh weight, height, or leaf/frond count reported or applicable - see next line); Plants/m2 (density is reported by mass, g/m2, not plant count). Plant height and Leaf count recorded NA: L. minor has no stem separate from the leaves (fused into a single ‘frond’ structure) and was not analysed for discrete leaf/frond counts anywhere in the paper (p.2).

Plant Measurements

Trial	System	Category	Analyte	Value	Unit	Sig.	Location
camargocastellanosSystemManagementLemna2022-T3	AP	proximate	Crude protein	30.0	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	proximate	Neutral detergent fibre (NDF)	34.16	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	proximate	Acid detergent fibre (ADF)	15.88	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	proximate	Lignin	6.07	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	proximate	Ash	19.77	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	proximate	Gross energy	3490	cal/g	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	mineral	Calcium (Ca)	2.02	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	mineral	Phosphorus (P)	1.1	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T3	AP	mineral	Nitrogen (N)	4.8	%	NR	Table 4 footnote c, p.10
camargocastellanosSystemManagementLemna2022-T4	AP	proximate	Crude protein	30.0	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	proximate	Neutral detergent fibre (NDF)	34.16	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	proximate	Acid detergent fibre (ADF)	15.88	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	proximate	Lignin	6.07	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	proximate	Ash	19.77	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	proximate	Gross energy	3490	cal/g	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	mineral	Calcium (Ca)	2.02	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	mineral	Phosphorus (P)	1.1	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T4	AP	mineral	Nitrogen (N)	4.8	%	NR	Table 4 footnote c, p.10
camargocastellanosSystemManagementLemna2022-T5	AP	proximate	Crude protein	30.0	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	proximate	Neutral detergent fibre (NDF)	34.16	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	proximate	Acid detergent fibre (ADF)	15.88	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	proximate	Lignin	6.07	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	proximate	Ash	19.77	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	proximate	Gross energy	3490	cal/g	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	mineral	Calcium (Ca)	2.02	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	mineral	Phosphorus (P)	1.1	%	NR	Section 3.2, p.6
camargocastellanosSystemManagementLemna2022-T5	AP	mineral	Nitrogen (N)	4.8	%	NR	Table 4 footnote c, p.10