Plant Care
- • Climate Control & VPD16
- • Disease & Pest Management14
- • Nutrient Solutions & EC34
- • Plant Health Monitoring7
Inputs
10 parameters · live recalculation on every change
M²
1m²
10m² default
1000m²
$
500$
5000$ default
100000$
KG/MO
5kg/mo
50kg/mo default
1000kg/mo
Advanced Settings — Deterministic Corrections
H/WK
2h/wk
10h/wk default
80h/wk
$/KWH
0.05$/kWh
0.15$/kWh default
1$/kWh
M
1.5m
2.5m default
10m
Deterministic model
10 inputs · 10 outputs
Runs 100% in your browser
This is a deterministic model: the same inputs always produce the same outputs, calculated entirely in your browser with nothing sent to any server. It is a planning aid — not a quote, not a dosing instruction, and not a yield forecast. Treat every line as a working estimate and validate it against your own prices and measurements.
It models one system: The systems-decision blueprint for a hydroponic grow. Enter the floor area, build budget, your experience level, the crop you want and the monthly yield target, and the engine scores eight systems — kratky, DWC, NFT, ebb & flow, drip, vertical tower, RDWC and aeroponics — with the archived experience ×1.5, crop ×1.5 and budget ×1.25 weighting, normalized into a 40–95% match band. It then sizes the exact build: kratky tanks, NFT channels stepped on the slope rule, and vertical tower count, plus build cost, payback months, water at 10 L per kg of harvest per day, photoperiod energy, the container-versus-warehouse reality check (~$50k capex vs $200k+ at 3x yield), and the green-to-red safety read.
What the Hydroponic System Selector Quiz — Kratky, NFT & Vertical Tower Blueprint returns
The engine computes 10 outputs from your 10 inputs. The headline number is Recommended System, alongside Kratky Tanks, NFT Channels, Vertical Towers. Every output updates live as you change a parameter.
What it does not do
Outputs depend on the inputs and assumptions shown here. Confirm relevant measurements and local conditions before acting.
STEP 01
Score the eight systems — kratky, DWC, NFT, ebb & flow, drip, vertical tower, RDWC, aeroponics — with experience ×1.5, crop ×1.5 and budget ×1.25 weights, then normalize into the 40–95% band and read the top-two gap as confidence.
STEP 02
Size the kratky arm: tanks = target yield ÷ 2.5 kg per tank. On the 10 m² beginner case that is 50 kg ÷ 2.5 = 20 passive tanks.
STEP 03
Set the NFT arm on the slope rule — slope % = drop ÷ run length × 100 — 12 ft at 2.5% means a 3.6 in drop, then count channels from 20 kg per channel: 200 kg ÷ 20 = 10 channels.
STEP 04
Count vertical towers from the 20 kg per tower budget: 500 kg on 5 m headroom → 25 towers, stepped at 30–42 in centers.
STEP 05
Cost the build — base + units × unit cost — and solve payback against monthly revenue minus the photoperiod operating cost.
STEP 06
Read the last three arms: water at 10 L/kg/day, lighting energy at system watts × 18 h ÷ 1000 (kratky at 0 W), and the safety band from experience × system × build cost — green for a beginner kratky, red for expert tower/raceway scale.
S_i = \frac{1.5\,E_i + 1.5\,C_i + 1.25\,B_i + A_i + Y_i + 0.75\,L_i + 0.50\,P_i}{8.0} \; \to \;[40,95]\%
System score — experience and crop weight ×1.5, budget ×1.25, then a 40–95% match band over the eight scored systems
N_{tanks} = \left\lceil \frac{Y}{n_{plants}^{tank} \cdot m_{kg}^{tank}} \right\rceil = \left\lceil \frac{Y}{2.5\, \text{kg}} \right\rceil
Kratky tanks — the target yield divided by the 2.5 kg each passive tank delivers (5 plants × 0.5 kg)
\text{Slope}\% = \frac{h_{drop}}{L_{run}} \cdot 100 \qquad \Rightarrow \; h_{drop} = L_{run} \cdot 12 \cdot \frac{\text{Slope}\%}{100}
NFT slope — the archived drop rule: a 12 ft channel at 2.5% falls 3.6 in, flowing 1.5 L/min (Manning n = 0.012 heuristic)
N_{ch} = \left\lceil \frac{Y}{n_{plants}^{ch} \cdot m_{kg}^{ch}} \right\rceil = \left\lceil \frac{Y}{20\, \text{kg}} \right\rceil
NFT channels — each 8-ft run of 4-in channel carries a 20 kg harvest line (40 plants × 0.5 kg)
N_{tower} = \left\lceil \frac{Y}{m_{kg}^{tower}} \right\rceil = \left\lceil \frac{Y}{20\, \text{kg}} \right\rceil
Vertical towers — a 7-ft tower at 8-in pocket pitch carries a 20 kg harvest budget at ~13 fruiting plants
C = C_{base} + N \cdot c_{unit}
Build cost — the system base gear plus each sized unit at its unit cost
\text{ROI} = \frac{C}{Y \cdot p_{kg} \, - \, C_{op}} \qquad (C_{op} = E_{kWh} \cdot 30 \cdot r)
Payback months — build cost over monthly revenue minus the photoperiod operating cost
W = \frac{Y}{30} \cdot 10 \quad \frac{\text{L}}{\text{day}}
Water use — 10 L per kg of harvest per day, pro-rated from the monthly target
The selector weights follow the archived quiz exactly — experience ×1.5, crop ×1.5 and budget ×1.25 — with space, capacity, labor, energy and maintenance rounding out the score before the 40–95% readability band and the top-two-gap confidence read.
Kratky is the passive arm: under $80 per tank, 0 W, beginner-grade and about 15 minutes of weekly care — but the archives warn it is "not for heavy tomatoes", because heavy fruiting crops outrun the static air-gap reservoir.
The NFT slope rule comes straight from the archived nft-slope tool: drop in inches = run length in feet × 12 × slope % ÷ 100. A 12 ft channel at 2.5% falls 3.6 in and the sweet-spot current is 1.5 L/min inside the 0.2–6 L/min band, sized with the Manning n = 0.012 heuristic.
Towers budget by crop: lettuce ≈150 g, basil ≈45 g, spinach ≈35 g, kale ≈220 g, strawberry ≈350 g, pepper ≈1.5 kg, cucumber ≈2.4 kg, bush tomato ≈2.8 kg, microgreens ≈8 g per plant — planted at the 4–18 in pocket-pitch optimum line.
The container-versus-warehouse reality check: a shipping-container build lands near $50k capex while a warehouse build tops $200k+ — yet the warehouse floor runs roughly 3x the yield. The HVAC arm confirms the shell math: container U = 1/5 conditions at ~$60/mo versus ~$14/mo for a warehouse U = 1/22.
Water and energy are the daily bills: 10 L per kg of harvest per day — so a 50 kg/month grow drinks ~17 L/day — and lighting energy is system watts × 18 h photoperiod ÷ 1000, with the kratky arm at a literal 0 W.
- Selector: eight systems — kratky, DWC, NFT, ebb & flow, drip, vertical tower, RDWC, aeroponics — scored with experience ×1.5, crop ×1.5 and budget ×1.25 weights, normalized into a 40–95% match band; the top-two gap reads confidence (archived selector methodology).
- Kratky: tanks = target yield ÷ (plants per tank × kg per plant) at 2.5 kg/tank; the passive air-gap arm runs under $80 per tank, 0 W, beginner-grade and roughly 15 min/week — but it is "not for heavy tomatoes".
- NFT slope: slope % = drop ÷ run length × 100; a 12 ft channel at 2.5% runs a 3.6 in drop and a 1.5 L/min current (the archived 0.2–6 L/min band, Manning n = 0.012 heuristic).
- Vertical: tower count = target yield ÷ 20 kg per tower; per-plant figures run lettuce ≈150 g, basil ≈45 g, kale ≈220 g, strawberry ≈350 g, pepper ≈1.5 kg, cucumber ≈2.4 kg, bush tomato ≈2.8 kg, microgreens ≈8 g with optimal pocket pitch 4–18 in.
- Reality check: a container build lands near $50k capex versus $200k+ for a warehouse at ~3x yield; the HVAC arm prices the shells at U = 1/5 vs 1/22 — roughly $60/mo vs $14/mo to condition.
- Water & energy: water ≈ 10 L per kg of harvest per day; lighting energy = system watts × 18 h photoperiod ÷ 1000, with the kratky arm at 0 W.
This model combines the earlier System-selector-quiz, Kratky-calculator, Nft-slope, Vertical-tower-yield, Container-farming-vs-warehouse-reality-check models.
Q1: Which hydroponic system is best for a beginner? ▾
The selector points novices at passive kratky: no pump, no timer, 0 W of water-side power, and roughly 15 minutes of care a week per tank. In the 10 m² beginner case with a leafy crop it scores a ~95% match and answers the 50 kg/month target with 20 tanks at about $600. The old system-selector archive warns only that heavy tomatoes-overwhelm the static air-gap, so beginners with a fruiting crop are steered toward DWC or NFT instead.
Q2: How many kratky containers do I need for my yield target? ▾
Tanks = monthly yield ÷ 2.5 kg per tank. A 50 kg/month leafy target needs 20 tanks, a 200 kg target needs 80, and a 500 kg target needs 200 — which is where the labor arm votes against passive kratky at scale: 200 tanks at 0.1 h/week each eats 20 hours of a 10-hour week. Each tank refills on the archived 0.55 / 0.92 fill-and-refill schedule, roughly every two weeks at leafy water demand.
Q3: What slope does an NFT channel need? ▾
The archived slope rule is slope % = drop ÷ run length × 100 — or drop in inches = run length in feet × 12 × slope % ÷ 100. A 12 ft channel at 2.5% falls 3.6 in and flows the 1.5 L/min sweet spot, inside the 0.2–6 L/min band sized with the Manning n = 0.012 heuristic. The selector sizes the channel count separately, at 20 kg of harvest per channel.
Q4: How many vertical towers do I need? ▾
Towers = monthly yield ÷ 20 kg per tower, stepped at 30–42 in centers under your vertical headroom. A 500 kg/month fruiting grow on 100 m² with 5 m of air answers with 25 towers. The per-plant economics come from the archive: lettuce ~150 g, kale ~220 g, strawberry ~350 g, pepper ~1.5 kg, cucumber ~2.4 kg and bush tomato ~2.8 kg per plant, at the 4–18 in pocket-pitch optimum.
Q5: Container farm or warehouse — which is the better build? ▾
At commercial scale the reality check is stark: a shipping-container build lands near $50k of capex while a warehouse build tops $200k+ — yet the warehouse floor runs roughly 3x the yield. The archived HVAC arm adds the shell math: a container shell (U = 1/5) costs about $60/mo to condition versus ~$14/mo for a warehouse shell (U = 1/22). Below $50k of budget the engine skips the capex debate and sticks to kratky, NFT and tower economics.
Q6: How much water and energy does my system use per day? ▾
Water runs at 10 L per kg of harvest per day — a 50 kg/month grow drinks about 17 L/day, a 200 kg/month grow about 67 L/day. Energy is system watts × the 18 h photoperiod ÷ 1000: the kratky arm is a literal 0 W, NFT channels run about 40 W each, and towers about 12 W each — a 25-tower build draws roughly 5.4 kWh/day before lights.