UseCalcPro
Home
MathFinanceHealthConstructionAutoPetsGardenCraftsFood & BrewingToolsSportsMarineEducationTravel
Blog
  1. Home
  2. Garden

Hydroponics Nutrient Calculator

Calculate nutrient solution strength

Nutrients (A+B)

80 ml each

Target EC

1.4 mS/cm

Target PPM

980

Part A

80

ml

Part B

80

ml

Target EC

1.4 mS/cm

Target PPM

980

pH Adjustment

pH Down (estimated)

Adjust to pH 5.8-6.2

10 ml

Nutrient Quantities

Part A Nutrients80.0 ml
Part B Nutrients80.0 ml
pH Down10.0 ml

Mixing Tips

Never Mix A + B Concentrated

Always add Part A to water first, stir, then add Part B.

Adjust pH Last

Add nutrients first, then adjust pH to 5.8-6.2 range.

Find a Landscaper Near You

Get free quotes from landscaping professionals near you

Angi
Angi4.7/5

Verified reviews & background checks

Get Free Quotes

Showing results for your area

Example Calculations

120-Gallon Reservoir, Vegetative Stage, Normal Strength

Inputs

Reservoir Size20 gallons
Growth StageVegetative
Nutrient StrengthNormal (100%)

Result

Target EC / PPM1.40 EC / 980 PPM
Part A80 ml
Part B80 ml
pH Down10.0 ml

EC = 1.4 x 1.0 = 1.40. PPM = 1.40 x 700 = 980. Part A = 20 x 4 x 1.0 = 80 ml. Part B = 80 ml. pH Down = 20 x 0.5 = 10.0 ml.

210-Gallon Reservoir, Flowering Stage, Heavy Strength

Inputs

Reservoir Size10 gallons
Growth StageFlowering
Nutrient StrengthHeavy (125%)

Result

Target EC / PPM2.25 EC / 1575 PPM
Part A50 ml
Part B50 ml
pH Down5.0 ml

EC = 1.8 x 1.25 = 2.25. PPM = 2.25 x 700 = 1575. Part A = 10 x 4 x 1.25 = 50 ml. Part B = 50 ml. pH Down = 10 x 0.5 = 5.0 ml.

Frequently Asked Questions

Q

What EC/PPM should I use for hydroponics?

Seedlings: 0.5-0.8 EC (350-560 PPM). Vegetative: 1.0-1.6 EC (700-1120 PPM). Flowering/Fruiting: 1.6-2.4 EC (1120-1680 PPM). Adjust based on plant response.

  • Start seedlings at 0.5 EC and increase by 0.2 EC per week until reaching target stage EC
  • Lettuce and herbs prefer lower EC (0.8–1.2); tomatoes and peppers need higher EC (1.8–2.4)
  • If leaf tips burn (brown edges), reduce EC by 0.2–0.4 immediately
  • If EC rises between top-offs, plants are drinking more water than nutrients – dilute with plain water
  • If EC drops between top-offs, plants are consuming nutrients fast – top off with full-strength solution
Growth StageEC RangePPM (700 scale)
Seedlings/Clones0.5–0.8350–560
Early Vegetative0.8–1.2560–840
Late Vegetative1.2–1.6840–1120
Flowering/Fruiting1.6–2.41120–1680
Q

How do I convert EC to PPM?

PPM = EC × 500 (Hanna scale) or EC × 700 (Truncheon scale). Most nutrient companies use the 700 scale. An EC of 2.0 equals 1400 PPM on the 700 scale.

  • Hanna/HM Digital meters use 500 scale: EC 2.0 = 1,000 PPM
  • Truncheon/BlueLab meters use 700 scale: EC 2.0 = 1,400 PPM
  • Check your meter manual to know which scale it uses – miscalibration is a common mistake
  • EC is the universal standard; PPM varies by manufacturer, so always note which scale you use
  • Calibrate your EC meter monthly with 1.413 EC (or 2.76 EC) reference solution for accurate readings
Q

How often should I change hydroponic nutrients?

Change the reservoir every 1-2 weeks, or when nutrient levels become unbalanced. Top off with plain pH-adjusted water between changes to maintain concentration.

  • Small reservoirs (5–10 gal): change weekly since nutrient ratios shift faster
  • Larger reservoirs (20+ gal): change every 10–14 days for stable nutrient balance
  • Top off with pH-adjusted plain water (pH 5.8–6.0) when level drops 10–20%
  • Full reservoir dump costs $2–$5 in nutrients – cheaper than recovering stressed plants
  • Clean and sanitize the reservoir with hydrogen peroxide (3%) between nutrient changes
Q

What pH is best for hydroponics?

Most plants prefer pH 5.5-6.5, with 5.8-6.2 being ideal. Some nutrients become unavailable outside this range. Check and adjust pH daily.

  • Target 5.8–6.0 for most leafy greens and herbs; 5.8–6.2 for tomatoes and peppers
  • pH above 6.5 locks out iron and manganese – causes yellowing between leaf veins
  • pH below 5.5 locks out calcium and magnesium – causes brown spots and stunted growth
  • Always add nutrients to water first, then adjust pH – nutrients shift pH significantly
  • Use phosphoric acid (pH Down) at 1–2 ml per gallon; potassium hydroxide (pH Up) at 0.5–1 ml per gallon

Related Calculators

Aquaponics Calculator

Calculate fish to plant ratios

Unit Converter

Convert measurements

Irrigation Calculator — Water & Scheduling

Calculate weekly water needs for lawns, vegetables, shrubs, and trees by soil type, sun exposure, and climate. Get gallons, runtime, and drip emitter counts.

Garden Irrigation Timer Calculator

Calculate sprinkler run times per zone based on plant type, soil, and weather season. Includes cycle/soak scheduling and monthly water cost estimates.

Seed Starting Calculator — When to Start Seeds Indoors 2026

Find exactly when to start seeds indoors by USDA zone. Get a personalized planting schedule with indoor start dates, transplant timing, and harvest windows.

Frost Date Calculator - Planting Schedule by Zone

Look up frost dates by USDA zone and get a planting schedule for vegetables and herbs. See last spring frost, first fall frost, and growing season length.

Related Resources

Garden Watering Calculator: How Much Water Does Your Garden Really Need?

Read our guide

When to Start Seeds Indoors: Frost Date Calculator & Planting Schedule

Read our guide

Age Calculator

Calculate exact age

Date Calculator

Calculate date differences

Unit Converter

Convert between units

More Garden Calculators

Plan your growing systems

View All

Last Updated: Mar 26, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

UseCalcPro
FinanceHealthMath

© 2026 UseCalcPro