Calculate how many grams of soluble fertilizer to dissolve for a target nitrogen concentration in a tank.
| Fertilizer mass | – |
Use this calculator to mix a greenhouse or hydroponic feed tank to a target nitrogen level. Enter the product's nitrogen percentage, the target N in ppm (mg/L), and the tank volume. The calculator tracks nitrogen only; potassium and phosphorus on the bag are ignored.
The calculation is: grams of product = (target ppm × tank litres) ÷ (percent N × 10). Example: 100 ppm N, 20% N, 10 L → 5 g. Tank volume can be entered in litres (L) or US gallons (gal); gallons are converted to litres before mixing. The fertilizer mass is reported in grams.
Percent N must be positive (the first number in a 20-10-20 analysis is 20). Many plants sit around 100–200 ppm N; follow the crop sheet rather than this range alone. This is a mixing-tank number, not a fertigation schedule.
Nitrogen in product (%): The N on the bag as a percent.
Target N (ppm): Desired nitrogen in the finished solution, in mg/L (ppm).
Tank volume: How much solution you are mixing. Enter the value in L or gal.
Fertilizer mass: Mass of product to dissolve.
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