Hy-Gen pH Down is highly concentrated and good value for money, however as a Dangerous Good it is only available for Click & Collect only as the contents are Hazardous. Check out Flairform pH Down, which can be shipped to you.
pH up and pH down are tank controllers that will adjust your solution to the desired pH. pH is a measure of the acidity or alkalinity of a solution. The pH scale ranges from 0 to 14. pH 7.0 is considered neutral and is based on pure water.
Solutions with a pH less than 7 are considered acidic, while those above 7 are considered basic (alkaline). pH effects nutrient uptake for most plants.
Recommended pH range for most plants is 5.9 to 6.3.