ESSENTIALS pH Down
Essentials pH adjusters work simply by altering the pH of a solution. If the current pH is at 5 (slightly acidic) a solution of alkaline (pH UP) is added to raise the solution to the desired level. This also works in reverse. Essentials pH UP and DOWN are supplied in 2 strengths.
Standard pH adjusters, highly concentrated and favoured by professional growers using large reservoirs.
pH UP potassium hydroxide 50% strength
pH DOWN phosphoric acid 81% strength