Nutrifield pH 4

These are solutions with precisely defined pH values. 

Your pH metre has to be calibrated if it doesn't read pH 4 when the probe is inserted into the buffer.

We advise checking the metre with pH 7 buffer at least once per week and pH 4 buffer at least once per month. There are calibration instructions included with every pH metre. When calibrating, dispense of the calibration solution and pour enough buffer from the bottle to cover the glass end of the probe. Returning used buffer to the bottle it was packaged in is not recommended.

Correct pH of hydroponic nutrient solutions is critical. Mineral absorption by the roots is pH dependent.

If the pH is outside the range of pH 5.5 to pH 6.5 then plants will have increasing difficulty absorbing minerals and a mineral deficiency would soon develop even though in all other respects the hydroponic nutrient is OK.

The pH should be checked when the nutrient solution is first made, and if used in a recirculating system, the pH should be checked every day.

Hydroponic fertiliser solutions must have the proper pH. The pH level affects the roots' ability to absorb minerals.