Enter Your Mix Details
Example Data Table
Sample scenarios show typical two-part mixing outcomes.
| Stage | Volume (L) | Strength | A (mL/L) | B (mL/L) | A total (mL) | B total (mL) |
|---|---|---|---|---|---|---|
| Seedling / Cuttings | 10 | 75% | 0.5 | 0.5 | 4.5 | 4.5 |
| Vegetative Growth | 20 | 100% | 1.4 | 1.4 | 28 | 28 |
| Flowering / Fruiting | 30 | 110% | 2 | 2.2 | 59.4 | 66 |
Formula Used
This calculator follows label-style dosing based on water volume.
- Convert volume to liters:
L = gal × 3.785411784 - Apply strength factor:
rate_eff = rate × (strength% ÷ 100) - Compute totals:
A_total = A_rate_eff × L,B_total = B_rate_eff × L - Optional estimates:
PPM = (A_rate_eff + B_rate_eff) × ppm_factor - Optional estimates:
EC = (A_rate_eff + B_rate_eff) × ec_factor
Factors vary by brand, water, and meters. Use your tested values.
How to Use This Calculator
- Fill your reservoir with the desired water volume.
- Select a growth-stage preset or choose Custom dosing.
- Adjust strength if you want lighter or stronger feeding.
- Press Calculate to see totals above the form.
- Add Part A, stir well, then add Part B.
- Download CSV or PDF to keep mixing records.
Why two-part nutrients stay more stable
Two-part feeds separate ingredients that can react when concentrated. Part A often carries calcium and micronutrients, while Part B commonly contains sulfates and phosphates. Separation protects solubility and shelf life. When each part is diluted into water first, nutrients remain available. This calculator uses mL per liter rates, then scales them to your reservoir volume for repeatable strength.
Choosing a starting rate for your crop stage
Begin gently for seedlings and new cuttings, then increase during vigorous vegetative growth. Fruiting crops may tolerate higher doses, but the best rate depends on cultivar, light, temperature, and root oxygen. Use presets as a baseline and adjust the strength percentage in small steps. If tips burn or leaves claw, reduce strength and review watering frequency.
Scaling your reservoir without dosing errors
Errors rise when changing bucket sizes or mixing multiple batches. Convert gallons to liters, apply the strength factor, and compute total milliliters for each part. Measure with a syringe for small mixes and a marked jug for tanks. Use rounding to match your tools. Ensure the entered volume matches actual water, not container capacity.
Using EC and PPM estimates responsibly
EC and PPM vary with meter calibration, temperature, and source water. If you know your product’s response, enter an EC or PPM factor per total mL/L to estimate a target. Treat it as guidance, then confirm with your meter after mixing. Adjust gradually. With very soft water, you may need extra calcium or magnesium for stability.
Mixing order, water quality, and record keeping
Add Part A to water, mix well, then add Part B. This reduces localized concentration and helps avoid clouding or deposits. Keep water moving with a pump, and avoid very cold water. Record volume, rates, and plant response. CSV and PDF exports make it easy to compare batches across growth stages and troubleshoot faster. Label your measuring tools and rinse them after use to prevent cross contamination and keep concentrates accurate over time.
FAQs
What volume should I enter for a recirculating system?
Enter the real liters in the reservoir after filling. Include only water that will be mixed with nutrients, not dry container size.
Can I mix Part A and Part B together first?
No. Combine each part with water separately. Mixing concentrates can cause precipitation, locking nutrients away and clogging lines.
How do I choose the best strength percentage?
Start at 70–90% for sensitive plants, then increase in 5–10% steps. Watch leaf tips, color, and growth rate before changing again.
Why do my EC and PPM readings differ from estimates?
Meters vary by scale, temperature compensation, and calibration. Source water also adds background salts. Use estimates for planning, then verify with your own meter.
Is the gallon conversion US or imperial?
The calculator uses US gallons. If you use imperial gallons, convert to liters first, then enter liters for the best accuracy.
Should I adjust pH before or after adding nutrients?
Adjust after nutrients are fully mixed and circulating. Nutrients change pH, so stabilizing after mixing gives a more reliable reading.
Safety reminder: Avoid mixing concentrates together. Add each part to water separately.