Skip to main content
Calcimator

EC and pH Adjustment

Calculate how much pH up/down solution and nutrient concentrate to add to reach target EC and pH levels in your hydroponic reservoir.

Inputs

mS/cm
mS/cm
gal

Results

EC Action

Add nutrients to raise EC

pH Action

Add pH Down (phosphoric/citric acid)

Nutrient Concentrate to Add53.3 mL
Fresh Water to Add (dilute)0 gal
pH Down Solution7 mL
pH Up Solution0 mL
Current PPM (500 scale)700 ppm
Target PPM (500 scale)1,260 ppm
Reservoir Liters75.71
How to Use This Calculator
  1. Measure your reservoir's current EC (mS/cm) and target EC for your crop stage — seedlings ~0.8–1.2, fruiting crops ~2.0–3.0.
  2. Measure the current pH and enter your target pH — most crops prefer 5.8–6.2 in hydro systems.
  3. Enter your reservoir size in gallons so the calculator can compute exact dosing volumes.
  4. Review the EC Action output: add Nutrient Concentrate (mL) to raise EC, or add Fresh Water (gal) to lower it.
  5. Follow the pH Action: add the recommended pH Down (mL) or pH Up (mL) solution, then re-check after 15 minutes.

What each input means

Current EC
Current electrical conductivity of your reservoir solution in millisiemens per centimeter. Measure with a calibrated EC meter.
Target EC
Desired EC level. Leafy greens: 0.8-1.5 mS/cm. Tomatoes/peppers: 2.0-3.5 mS/cm. Herbs: 1.0-1.8 mS/cm.
Current pH
Current pH of the reservoir solution measured with a calibrated pH meter or test drops.
Target pH
Desired pH level. Most hydroponic crops thrive at 5.5-6.5. Adjust incrementally (0.5 at a time) and retest.
Reservoir Size
Current volume of nutrient solution in the reservoir in US gallons. Larger volumes require proportionally more adjustment.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Current EC = 1, Target EC = 1.8, Current pH = 7.2, Target pH = 5.8 = 5 input(s) provided
  2. Calculate EC Action
    EC Action
    Add nutrients to raise EC = Add nutrients to raise EC
  3. Calculate pH Action
    pH Action
    Add pH Down (phosphoric/citric acid) = Add pH Down (phosphoric/citric acid)
  4. Calculate Nutrient Concentrate to Add
    Nutrient Concentrate to Add
    53.3 = 53.3
  5. Calculate Fresh Water to Add
    Fresh Water to Add
    0 = 0

Engine last updated .

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Hydroponics

Nutrient Solution Calculator

Calculate hydroponic nutrient solution concentrations (N, P, K, Ca, Mg) in ppm from concentrate dosage, solution strength, and reservoir size.

Hydroponics

Grow Light Calculator

Calculate the number of grow light fixtures needed and Daily Light Integral (DLI) from PPFD, photoperiod, and canopy area for optimal indoor plant growth.

Cannabis

Nutrient Schedule Calculator

Feed concentration by growth stage and medium.

Food Science

pH Adjustment Calculator

Calculate acid dose needed to reach a target pH for food preservation, using buffer capacity and acid type.

Hydroponics

NFT Channel Design

Design a Nutrient Film Technique (NFT) hydroponic system by calculating channel count, pump capacity, plant spacing, and flow velocity from your plant count and layout.

More in Agriculture & Farming.