AB mix nutrient calculator

For hydroponic systems using A and B nutrients mixed in equal amounts.

Choose a crop

Crop

Target from source: Lactuca sativa

EC 1.2–1.8 mS/cm (600–900 ppm)

pH 6–7

05001,0001,5002,0002,500

ppm (500)

Source: Oklahoma State University Extension (Dunn & Singh), HLA-6722 (2017)

Melon, water spinach, and local bayam aren't listed because we haven't found a verified source yet.

Your meter

What your meter shows

Most low-cost TDS meters use the 500 scale. Check your meter's manual.

PPM 500 scalePPM 700 scalePPM 640 scaleEC (mS/cm)

What do you want to do?

Fill a new tankAdjust a tank

Water in the tank

litres

How to calculate

Follow the label doseReach a target EC

Label dose per litre (for A and B each)

Once EC is right, check pH

pH target for Lettuce: 6–7. If it's too high, add pH down a little at a time, stir, wait a few minutes, and measure again. Always check pH after EC, not before.

EC and PPM converter

Enter one number; the others are calculated.

EC (mS/cm)

mS/cm

PPM 500 scale

ppm

PPM 700 scale

ppm

Limits of this calculation

EC is assumed to rise in proportion to the dose. This is an estimate; measure again after mixing.
The volume of concentrate added is ignored because it's small compared with the tank.
Calibrate your meter regularly. Readings from an uncalibrated meter can be far off.
Source targets are general ranges, not a recipe for every variety, medium, or climate.