Hydroponic Nutrient Volume Mixer
Scale a Part A/B feed chart to your exact reservoir size.
Result
Always follow your specific nutrient label and verify with an EC meter. Doses vary by brand, crop and stage.
History
What it is
This mixer scales a two-part (Part A / Part B) feed chart to your exact reservoir size. You enter the dose your nutrient label recommends per unit of water and your reservoir volume, and it returns the total millilitres of each part to add.
Who should use it
Hydroponic growers using two-part base nutrients who want to mix the right amount for any reservoir size without guessing or over-pouring.
How to use it
- Enter your reservoir volume.
- Enter the Part A dose from the bottle label (per gallon or per litre, matching your region).
- Enter the Part B dose the same way.
- Read the total millilitres of Part A and Part B to add to the reservoir.
- Add Part A first, mix, then add Part B, and finally check EC and pH.
Example calculation
Worked example
For a 20-gallon reservoir with a label dose of 8 mL/gal for each part, you add 160 mL of Part A and 160 mL of Part B (8 × 20). Always add and stir one part fully before adding the next to avoid nutrient lockout.
Formulas used
Total Part X (mL) = dose_per_litre · reservoir_litres
How to read your result
Treat the label dose as a starting point. After mixing, measure EC — if it is above your target for the stage, dilute with water; if below, add a little more nutrient. Re-check pH last, because adding nutrients shifts it.
Recommended ranges
| Reservoir | Part A | Part B |
|---|---|---|
| 10 L (2.6 gal) | 20 mL | 20 mL |
| 20 L (5.3 gal) | 40 mL | 40 mL |
| 50 L (13 gal) | 100 mL | 100 mL |
| 100 L (26 gal) | 200 mL | 200 mL |
Common mistakes to avoid
- Adding Part A and Part B together in concentrated form — they can react and precipitate. Always add separately and mix between.
- Mixing to the label dose without checking EC for your growth stage.
- Adjusting pH before the nutrients are fully mixed.
- Ignoring the nutrients already supplied by hard tap water.
Frequently asked questions
How much nutrient per litre or gallon?
Follow your product label as a starting dose, then verify with an EC meter. This calculator scales that label dose to your exact reservoir size.
Why add Part A and Part B separately?
Concentrated A and B can react and form insoluble precipitates. Adding each to the full water volume and mixing between prevents lockout.
Should I mix to the label dose exactly?
Use it as a baseline. Confirm with EC and adjust to the target strength for your crop and stage.
Do I check pH before or after mixing nutrients?
After. Nutrients change the solution's pH, so always mix fully, then measure and adjust pH last.
What order do I add things?
Fill with water, add Part A and stir, add Part B and stir, then check and adjust EC, and finally pH.