Hydroponic Nutrient Calculator
Select your hydroponic nutrient brand and crop growth stage to calculate the exact milliliter dosing amounts required for your reservoir—or construct a fully custom N-P-K target formula.
- Open dosing algorithms
- Runs 100% in-browser
- Auto EC-to-PPM conversion
System Configuration
If your mixed solution PPM doesn’t match your recipe, ensure your meter’s conversion factor matches this setting.
Nutrient Selection
Quick-Fill by Crop
Tap a crop to auto-fill a typical target EC for the growth stage selected above.
Calculation Results
Fill in the fields above and calculate a recipe
Nutrient Mix Volume
Elemental Balance
Hydroponic Nutrient Guide
Understanding solution chemistry guarantees healthier root zones and faster yields.
Understanding EC & PPM
Electrical Conductivity (EC) directly measures dissolved mineral salts. PPM is an approximation based on EC. Always prioritize absolute EC over calculated PPM.
Macronutrient Balance
Vegetative plants demand higher Nitrogen (N). During flowering and fruiting, shift ratios toward Phosphorus (P) and Potassium (K) to support bud sites.
Critical pH Importance
Maintain reservoir pH strictly between 5.5 and 6.5. Even perfect nutrient mixtures will “lock out” and become unavailable to roots if the pH drifts too high or low.
Flushing Frequency
Plants consume elements unevenly. Completely empty and replace your nutrient reservoir every 10–14 days to prevent toxic mineral buildup and severe pH drift.
Frequently Asked Questions
What is the difference between the 500 and 700 PPM scale?
Both scales convert the exact same EC (Electrical Conductivity) reading into a different PPM integer. A Hanna meter (US, 500 scale) and a Bluelab/Truncheon meter (EU, 700 scale) will display different PPM values for the identical solution. Always set the calculator scale to match your specific meter’s hardware setting, not your recipe source.
What EC should I run for leafy greens vs. fruiting plants?
Delicate leafy greens (lettuce, spinach) and culinary herbs require a lower EC concentration, generally between 1.0–1.4 EC. Heavy fruiting crops (tomatoes, bell peppers) demand a much stronger solution, typically scaling up to 1.8–2.6 EC during peak fruiting stages.
Is a higher EC solution always better for faster growth?
No. Pushing EC above the specific target range for a plant causes osmotic stress and “nutrient burn” (characterized by crispy, brown leaf margins), which stunts growth. If you suspect overfeeding, use our Hydro Doctor tool to diagnose the damage.
How often do I need to change my hydroponic nutrient solution?
For most recirculating home systems (DWC, NFT), execute a full reservoir drain and replacement every 7 to 14 days. Between flushes, top off the reservoir with fresh, pH-adjusted water (or a weak 0.5 EC solution) to compensate for evaporation and plant consumption.
Disclaimer: This calculator provides general chemical proportion guidance. Always cross-check against your specific manufacturer’s label instructions and adjust for starting tap water EC. © MistCulture.com