💦 Water Soluble Fertilizer Calculator
Mix nutrient solutions accurately by converting ppm targets, reservoir volume, and fertilizer analysis into grams or ounces.
Use the percentage of the nutrient you are targeting (e.g., nitrogen in 20-10-20).
How to Use This Calculator
Select target ppm
Determine the nutrient concentration recommended for your crop stage.
Enter tank volume
Include total reservoir size or injector stock solution volume.
Input fertilizer analysis
Use the nutrient percentage from the fertilizer label to compute required mass.
Formula
Fertilizer (g) = (ppm × VolumeL) ÷ (Nutrient% ÷ 100) ÷ 1000
1 ppm equals 1 mg/L. Convert gallons to liters, divide by nutrient fraction, then convert milligrams to grams.
Full Description
Water-soluble fertilizers provide precise nutrient delivery for hydroponics, fertigation, and greenhouse production. Calculating additions accurately prevents salt buildup and ensures consistent EC and pH management.
Always dissolve fertilizers in warm water before adding to reservoirs and verify final concentrations with EC or ppm meters.
Frequently Asked Questions
Can I target multiple nutrients?
Calculate each nutrient separately or use nutrient-specific fertilizer blends to meet targets.
How do injector ratios affect ppm?
Divide ppm by the injector ratio (e.g., 1:100) to determine stock solution concentration.
What about micros and calcium nitrate?
Add each fertilizer independently, accounting for its specific nutrient percentage.
Should I round up grams?
Yes. Slight overage is fine—verify with EC/ppm meters and adjust if needed.