Raising soil pH : (to make it more alkaline)
It is generally easier to make soil mixes more alkaline than it is to make them more acidic. The addition of dolomite lime, hardwood ash, bone meal, crushed marble, or crushed oyster shells will help to raise the soil pH.
by MisterIto
In soil: add dolomite limestone to the soil; use small amounts of hydrated lime.
Raising hydroponic pH : (to make it more alkaline)
In hydroponics: use potassium silicate, provides silicon at an effective doseage.
In bioponics/hydro-organics: add small amounts of sodium bicarbonate or lime.
Lowering soil pH : (to make it more acidic)
If your soil needs to be more acidic, sawdust, composted leaves, wood chips, cottonseed meal, leaf mold and especially peat moss, will lower the soil pH.
by MisterIto
bloodmeal/cottonseed meal during vegetative; bonemeal during flowering.
Lowering hydroponic pH : (to make it more acidic)
In hydroponics: use nitric acid during vegetative; phosphoric acid during flowering.
Contributed by: Spiritual.Fa
23-08-2003
Stabilizing pH with Dolomite lime
The best way to stable PH is by adding 1 ounce of Dolomite Lime per 1 gallon of planting soil.