Hydroponic Nutrient & Grams to Your Target EC
Mixes lettuce
Enter your tank size, target EC and dose rate to get the grams of nutrient to add, split into a two-part A/B mix, plus the target ppm.
Enter your reservoir
Next: dissolve 70 g of A then 70 g of B separately into the tank, check EC and adjust, then set pH to 5.5–6.5.
EC→ppm factor and g/L vary by nutrient brand; always add A and B separately to avoid precipitation, and verify with an EC/pH meter.
Hydroponic nutrients — key facts
- Target ppm
- EC × factor (500 or 700)
- Nutrient grams
- tank (L) × dose × target EC
- A/B split
- half each, added separately
- Leafy crops
- ≈ EC 1.4
- Fruiting crops
- ≈ EC 2.5
- pH range
- 5.5–6.5
- Never
- mix A and B concentrates
- Privacy
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Feed by the numbers, not by guesswork
In hydroponics there is no soil to buffer mistakes — the plant eats exactly what's in the tank, measured by EC for strength and pH for availability. Too weak and the crop starves; too strong and the roots burn. The art is mixing the right grams of nutrient into your volume of water to hit the target EC for the crop and its stage, then keeping calcium apart from sulphates and phosphates by dosing a two-part A/B formula separately.
This tool turns your tank size, dose rate and target EC into the grams of nutrient to add, the split between stock A and stock B, the dose in g/L and the target ppm on either the 500 or 700 scale. Use the leafy and fruiting targets as a guide, then always confirm the mixed solution with an EC and pH meter. Pair it with the Fertigation, Potting Mix and Fertilizer (NPK) tools for a complete feeding plan.
Hit your target EC
Grams scaled to your tank and crop strength.
Split A and B safely
Half each, added separately, no precipitation.
Read EC and ppm
Target ppm on the 500 or 700 scale.
Match the crop
Mild for leafy, stronger for fruiting.
Frequently Asked Questions
How do hydroponic nutrients work?+
Hydroponic plants have no soil, so they take everything they need from a balanced salt solution in the water. You measure that solution by its electrical conductivity (EC), which reflects the total dissolved salts and therefore the feed strength, and by its pH, which controls whether the plant can actually absorb each nutrient. Get both right and the crop thrives.
How are the nutrient grams calculated?+
Nutrient grams = tank volume (L) × dose (g/L per unit EC) × target EC. So a 100 L tank, a dose of 1 g/L per EC and a target EC of 1.8 needs 100 × 1 × 1.8 = 180 g. The dose figure comes from your specific product's mixing instructions, and the calculator scales it to your tank and target strength.
What is the EC-to-ppm relationship?+
ppm (parts per million of dissolved salts) is estimated from EC by a conversion factor: target ppm = EC × factor, where the factor is 500 on the US (Hanna) scale or 700 on the European (Eutech) scale. So EC 1.8 reads about 900 ppm on the 500 scale or 1260 ppm on the 700 scale — always note which scale your meter uses.
Why split into a two-part A/B mix?+
Concentrated calcium (in part A) and phosphates and sulphates (in part B) react and precipitate out as insoluble solids if mixed together undiluted. Splitting the feed into A and B stocks and adding each separately to the already-diluted tank keeps everything in solution. The tool gives roughly half the grams to each part.
What EC should leafy and fruiting crops get?+
Leafy crops like lettuce and herbs prefer a mild solution around EC 1.4, while fruiting crops like tomatoes, peppers and cucumbers want a stronger feed around EC 2.5, often raised further during heavy fruiting. Seedlings start lower and you build up; in hot weather plants drink more water than salts, so you may dilute slightly to hold EC.
What pH should the solution be?+
Keep hydroponic solution between pH 5.5 and 6.5 — the band where the full range of nutrients stays available. Outside it, elements like iron, calcium or phosphorus lock out even when present, causing deficiencies. Check pH after mixing and daily, and adjust with pH-up or pH-down; topping up with water usually nudges pH, so re-test.
How often should I change the solution?+
Plants take up water and nutrients at different rates, so EC and pH drift as the tank runs down. Top up with plain water and re-balance EC and pH between changes, and replace the whole solution every one to two weeks (sooner in heat or with heavy feeders) to reset the nutrient balance and avoid build-up of unused salts.
Do I add A and B at the same time?+
Add them separately. Stir part A fully into the diluted tank water first, let it disperse, then add part B and stir again — never combine the concentrated A and B stocks directly, or they precipitate. Mixing into a well-diluted tank, one part at a time, keeps calcium and sulphates apart until they're too dilute to react.
Does the calculator work for any nutrient brand?+
Yes — enter the dose rate (grams per litre per unit of EC, or the strength) from your own product's instructions and the tool scales it to your tank and target EC. Brands differ in concentration and formulation, so always start from the manufacturer's figures rather than a generic dose, and verify the mixed solution with an EC meter.
Are these figures exact?+
They're a reliable starting point. Source-water EC, temperature, crop stage and your specific product all shift the real result, so always mix, then measure the solution with an EC and pH meter and fine-tune. Treat the grams as a target to dose toward and confirm — never assume the calculated figure without checking the tank.