8 oz. Soda Ash (Sodium Carbonate) sold in pre-measured quantity to make 1 gallon RO/DI solution.
Soda Ash aka Sodium Carbonate is an aquarium supplement used in control of alkalinity and pH. Two cups per gallon mixed in a bucket. Can then be transferred to gallon container.
Soda Ash can be used alone or in combination with Sodium Bicarbonate.
Always test alkalinity and pH before and after each dosing. Each reef aquarium is unique in water quality, chemical nature, pH, temperature, and stability. Avoid changing pH more than +/- 0.2 per day. It is best to always avoid any large swings in any reef parameter.
Always use caution when handling any chemical. Do not breath or eat chemicals.