Hydroponics & vertical farming tools

Aim for pH 5.5–6.5 (most nutrients are available here) and set EC by crop: leafy greens and herbs 0.8–1.6 mS/cm, fruiting crops like tomato and cucumber 2.0–3.5 mS/cm, and seedlings around 0.5–1.0 mS/cm. Use the EC ↔ TDS converter to read any meter, and acid injection to drop high-alkalinity tap water into the target pH band.

A recirculating soilless system reuses its nutrient solution, so it typically uses 70–90% less water than open-field irrigation for the same yield — the Water Use Efficiency tool quantifies the yield per litre for your setup. Drain-to-waste systems save less but still beat flood irrigation.

NFT (nutrient film technique) runs a thin film of solution down sloped channels past bare roots — ideal for lightweight leafy crops. DWC (deep water culture) suspends roots in aerated solution. Media/drip systems grow in coco-coir, perlite or rockwool fed by drippers — best for heavy fruiting crops. The channel-layout and drip-flow tools size each.

Set channel length to your bench (usually ≤ 8–12 m so the film does not warm up or run out of oxygen), slope the channels 1:30 to 1:40 (about 2.5–3.3%), and space plant holes by crop (lettuce ~18–25 cm). The Hydroponic Channel Layout calculator returns channels, plant sites and total channel length from your bench dimensions.

A vertical rack multiplies a square metre of floor by the number of growing tiers — a 5-tier rack turns 1 m² of floor into roughly 4–5 m² of canopy (minus aisles and structure). The Vertical Farming Rack calculator returns the exact growing area, plant sites and footprint multiplier from your tiers, shelf size and spacing.

Microgreens are sown dense: roughly 10–15 g per standard 10×20 inch (≈ 0.13 m²) tray for small seeds like radish or broccoli, and 30–50 g for larger seeds like pea or sunflower. The Microgreens Seeding calculator scales seed per tray and the fresh-cut harvest across your rack.

Use separate A and B concentrated stock tanks: calcium nitrate goes in A, and phosphates and sulphates in B, because mixing them concentrated forms insoluble calcium phosphate/sulphate. The Stock Tank calculator builds both at a set dilution ratio (commonly 1:100) so an injector delivers a balanced feed.

Leafy greens want a daily light integral (DLI) of about 12–17 mol/m²/day, usually 14–18 hours of LED at moderate intensity. Day-neutral lettuce and most microgreens will not bolt under long days, but use the Photoperiod calculator for short-day or long-day crops where day length triggers flowering.

Vapour-pressure deficit of about 0.8–1.2 kPa keeps leafy crops transpiring without stress — too low and growth slows and disease rises, too high and stomata close. The VPD calculator turns your room temperature and humidity into kPa so you can adjust ventilation or misting.

Controlled-environment units carry high capital cost but high yield and price per area. Payback usually lands at 3–6 years for a well-run protected unit growing high-value greens, herbs or vine crops — the Polyhouse / CEA ROI calculator turns your capital, yield and margin into a payback period and annual return.

Multiply EC in mS/cm by a meter-specific factor: 500 (the US/Hanna scale) or 700 (the EU/Truncheon scale). So EC 2.0 mS/cm ≈ 1000 ppm on the 500 scale or 1400 ppm on the 700 scale — always check which scale your meter and recipe use with the EC ↔ TDS converter.

Top up daily with plain water to replace transpiration, correct EC and pH each day, and fully change the reservoir every 1–3 weeks (sooner for fast-feeding fruiting crops) to reset nutrient ratios that drift as plants take ions up unevenly. Track this with the Nutrient Use Efficiency tool.