Online Tool Store
Hydroponic Nutrient Calculator
Enter your reservoir volume and target EC/PPM to calculate how much of each nutrient concentrate to add for a balanced hydroponic solution.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Grow
—
ml to add
Micro
—
ml to add
Bloom
—
ml to add
Add each part separately, stirring well before adding the next — never mix concentrated nutrients together before diluting.
How it works
- Enter your reservoir volume and pick a growth stage (or switch to custom to set your own ml/L rate).
- The calculator multiplies your chosen dosage rate by the reservoir volume for each nutrient part.
- Add each part to your reservoir in order (Grow, then Micro, then Bloom), stirring between additions, and recheck EC/PPM with a meter afterward.
The formula
Each nutrient part's dose is a simple rate-times-volume calculation:
Dose (ml) = Reservoir volume (L) × Dosage rate (ml/L)
Example: a 20 L reservoir at the vegetative preset (2 ml/L Grow, 2 ml/L Micro, 1 ml/L Bloom) needs 40 ml Grow, 40 ml Micro, and 20 ml Bloom.
FAQ
Which nutrient systems does this support?
The calculator ships with dosage presets for common 3-part liquid systems (Grow/Micro/Bloom style) at seedling, vegetative, and bloom strength, plus a custom mode where you enter your own ml-per-liter rate for any brand.
Does it account for reservoir top-offs?
No — the amounts shown are for a single full-strength mix of your entered reservoir volume. If you top off with plain water between full changes, dilute nutrient concentration accordingly rather than dosing the top-off water at full strength.
Why are Grow, Micro, and Bloom different amounts?
3-part systems let you shift the nitrogen-phosphorus-potassium ratio across a plant's life cycle — vegetative growth favors more Grow/Micro (nitrogen), while flowering favors more Bloom (phosphorus/potassium) — so the calculator scales each part by your selected growth stage, not just a flat multiplier.
How we compare
| Feature | Online Tool Store | Manufacturer feed chart (PDF) | Doing the math by hand |
|---|---|---|---|
| Scales instantly to any reservoir size | ✓ | ✗ | ✗ |
| No sign-up | ✓ | ✓ | ✓ |
| Editable custom dosage rate | ✓ | ✗ | ✓ |
A feed chart tells you the rate; this does the multiplication for your exact reservoir size so you're not eyeballing a syringe against someone else's table.