pH stabiliser 6. 5A specially developed pH stabiliser for freshwater aquarium buffer 6. 5 pH provides a natural blend of salts and ingredients that gently adjust the pH value in fresh water to an optimal value of 6. 5. The product is ideal for discourse fish and scalars. Functions and benefits:- Stabilises the pH value to 6. 5. - Harmless to animals and plants. In combination with pH Increase or pH Decrease, each pH level can be reached safely and easily in the aquarium.