zdam20

I need to raise my alk a little so I can hit the 30 ppm of CO2 and still keep a resonable ph. I purchased some CaCO3 powder at a local health food store and I've got a couple of questions. How many grams of powder do I dissolve in how much water? Once that's answered, how much do I dose of the liquid? For example, my tank is 150 gallons and my kh=1.75. I'd like to raise the kh to 4.2-4.5. Any help would be appreciated.