Water Soluble Fert Calculator
Precision liquid nutrition for hydroponics and fertigation.
Enter your feeding requirements to calculate the precise weight of fertilizer salt needed. The AI will provide mixing safety and solubility advice.
✅ How to Calculate Liquid Fertilizer Ratios
The Water Soluble Fertilizer Calculator is an essential tool for professional greenhouse growers, hydroponic farmers, and intensive gardeners. Unlike granular fertilizers applied to soil, water-soluble fertilizers must be mixed into a solution at a specific PPM (Parts Per Million). This ensures that plants receive immediate, bioavailable nutrition without the risk of salt buildup or nutrient lockout.
This calculator determines exactly how many grams of dry fertilizer you need to dissolve into your water source to reach your target nutrient concentration. Whether you are mixing a 100-gallon reservoir for a deep water culture system or setting up an injector for a fertigation line, precision is the difference between a record harvest and root burn.
✅ The Formula for PPM
To find the weight of fertilizer required, we use the "75 Factor" which represents the constant used in US measurements to link PPM, percentage, and weight:
Grams = (Desired PPM × Gallons) ÷ (Nutrient % × 0.264)
*Standard constant for 1 gram per 100 gallons = 2.64 PPM at 100% purity.
✅ FAQ Section
What is PPM in hydroponics?
PPM stands for Parts Per Million. It measures the concentration of a specific nutrient (like Nitrogen) in your water. 150 PPM of Nitrogen is a standard "safe zone" for many vegetative crops, while fruiting plants may require 200+ PPM.
Can I mix different fertilizers together?
Be careful with Calcium and Phosphorus/Sulfur. If you mix high concentrations of Calcium Nitrate and Magnesium Sulfate (Epsom salt) in the same concentrated "Stock Tank," they will react and form gypsum, which will clog your lines and make nutrients unavailable to plants.
Does the water temperature matter?
Yes. Solubility decreases as water temperature drops. Most fertilizer salts dissolve best in water between 65°F and 80°F. Very cold water can lead to "precipitation," where the fertilizer stays in solid form at the bottom of the tank.
✅ Related Tools
Liquid Feeding & Hydroponics
Calculate the exact concentration (PPM) of nutrients for liquid feeding systems to prevent nutrient burn and ensure optimal growth.