Nutrient Mixing & Dilution Calculator

Nutrient Mixing & Dilution Calculator

Mix nutrients precisely every time. Use EC Target to calculate ml/gallon from your EC goal, Label Rate to convert manufacturer instructions, or C1V1 Dilution to weaken a stock solution. Questions? Talk to a Grow Expert.

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Nutrient Mixing & Dilution Calculator

Choose a tool: EC Target (1/2/3-part mix), Label Rate (ml/gal from label), or C1V1 Dilution (dilute a stock).

Tip: Set your target EC and reservoir volume — the calculator tells you exactly how many ml of each nutrient part to add per gallon.
Part A
How to use this calculator
  1. EC Target tab: Enter your target EC and source water EC. Choose 1-Part, 2-Part, or 3-Part and enter the EC contribution per ml/L from the nutrient label.
  2. Label Rate tab: Enter reservoir volume and add each nutrient with its label rate. Get total ml and a per-gallon recipe.
  3. C1V1 Dilution tab: Enter your stock concentration (C1), target concentration (C2), and final volume (V2). Get the exact stock volume to use (V1).
  4. Always add nutrients to water, not water to nutrients. For multi-part systems, add Micro first, then Grow, then Bloom.
  5. Verify with a calibrated EC pen after mixing — results are estimates based on manufacturer data.

EC formula: ml/L needed = (Target EC − Water EC) ÷ EC-per-ml/L  ·  C1V1 formula: V1 = (C2 × V2) ÷ C1

📊 Recipe Proportion Chart — See Each Part's Share Visual ▾

Each bar segment shows one nutrient part's proportion of the total recipe volume. Calculate using the EC Target or Label Rate tab first — the chart updates automatically. Hover or tap a segment to see exact amounts.

Nutrient EC & Dilution Quick Reference

Common EC targets by growth stage and crop type — hydroponics and coco
Growth Stage EC Target (mS/cm) PPM (500 Scale) PPM (700 Scale) Notes
Seedlings / Clones 0.4 – 0.8 200 – 400 280 – 560 Use only RO or very low EC water
Early Veg 0.8 – 1.4 400 – 700 560 – 980 Ramp up gradually over 1–2 weeks
Late Veg 1.4 – 2.0 700 – 1000 980 – 1400 Monitor runoff EC; keep under 3.0
Early Flower 2.0 – 2.4 1000 – 1200 1400 – 1680 Increase P and K ratios
Late Flower 2.4 – 2.8 1200 – 1400 1680 – 1960 Some growers flush last 1–2 weeks
Lettuces / Herbs 1.0 – 1.6 500 – 800 700 – 1120 Sensitive to high EC; keep runoff low
Tomatoes / Peppers 2.0 – 3.5 1000 – 1750 1400 – 2450 High EC improves fruit quality

Frequently Asked Questions

What EC should I target for cannabis in veg vs flower?
Typical vegetative EC targets range from 1.2–2.0 mS/cm. Flowering plants can handle 2.0–2.8 mS/cm depending on strain and grow medium. Start lower and increase gradually — reading runoff EC helps you spot salt buildup before it becomes a problem. Always account for your source water EC; most tap water adds 0.2–0.5 mS/cm before you add a single drop of nutrients.

How do I calculate ml per gallon from a nutrient label?
Multiply the label rate in ml/L by 3.785 to convert to ml per gallon. For example, 2 ml/L × 3.785 = 7.57 ml per gallon. Use the Label Rate tab in this calculator to do this automatically across multiple products at once. Always add Part A to the water before Part B to prevent precipitation in multi-part systems.

What is the C1V1=C2V2 formula used for?
C1V1=C2V2 is used to dilute a concentrated nutrient solution to a lower target concentration. C1 is your stock concentration, V1 is how much stock to use, C2 is the target concentration, and V2 is the final volume. Solve for V1: V1 = (C2 × V2) ÷ C1. The remaining volume (V2 − V1) is added as plain water to reach the final volume.

Why does my EC meter not match the calculator's estimate?
EC results vary based on your water source, nutrient brand, temperature, and whether you use the 500 or 700 PPM scale. The calculator uses general EC-per-ml/L values — your specific nutrient products may differ slightly. Always calibrate your EC pen with fresh calibration solution, and measure at 25°C (77°F) for consistent readings. Use manufacturer data for the most accurate EC-per-ml/L inputs.

How do I mix a 3-part nutrient system in the correct order?
Fill your reservoir with most of the final water volume first. Add Micro, stir well. Then add Grow, stir. Finally add Bloom and stir. Never mix concentrated A (Micro) and B (Bloom) directly — they react and form insoluble precipitates. Let each part disperse before adding the next, then top up to final volume and check EC and pH before use.

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