pH and Nutrients in Hydroponics

What pH means

pH measures how acidic or alkaline the nutrient solution is. Plants can only absorb nutrients well within a fairly narrow range, so pH matters even when the solution has plenty of nutrients.

Typical range

Many common crops grow well with a slightly acidic solution, usually around pH 5.5 to 6.5. Check the guidance for the plants you are growing, because some differ.

Testing and adjusting

• Test with a pH meter or a liquid test kit. Test after mixing and after every top-up.
• Adjust with pH up or pH down in small amounts, mix well, and test again.
• Keep a log if you are troubleshooting. Changes in pH often show up as yellowing leaves or slow growth.

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