Oct 23, 2019· ALUMINIUM SULPHATE HYDRATE Kibbled. ... Aluminium sulfate is sometimes used to reduce the pH of garden soil. The gardener can add Aluminum sulfate to the soil to reduce the pH level which in turn will result in the flowers of the Hydrangea turning a different color (see below).
Aluminum sulfate also lowers soil pH, but we do not recommend its use because of potential harmful side effects (aluminum toxicity to plant roots), which can significantly reduce plant growth. Elemental sulfur The most rapid reduction in soil pH is achieved by using elemental sulfur. When elemental sulfur (S) is mixed with the soil,