Thank you for your interest in Drs. Foster and Smith. It really depends on what you want your stock solution to be. A common formula out there is as follows, this can be used as part of a calcium/alkalinity 2 part dosing system:
• Fill gallon jug 5/6 full with RO/DI or distilled water and pour into an empty bucket/bowl.
• While stirring slowly add 2 level dry measuring cups of Sodium Carbonate.
• Once dissolved, use funnel to transfer solution to a gallon jug.
1 tsp(5ml) will raise the alkalinity approximately .7 kdh per 10 gallons. So you will have to do the math for whatever your tank volume is and how much you want to raise the alkalinity.
Slowly add the solution to high flow areas of the tank. Soda carbonate will increase PH., this is temporary but it is important to monitor PH while dosing to avoid raising PH more than than 0.20. Do not increase alkalinity levels more than 0.5meq/lt or 1.4 dkh per day. If necessary spread the suggested dose out and test between doses.