I was using Red Sea Coral Pro up until this week. It takes a half cup to reach roughly 1.0235 in a gallon of water. From my experience anyway. I switched to Coralife because I have green hair algae and my AWT test results showed high silica, somewhat high phosphate, and low calcium and magnesium. Because AWT also tested Red Sea Coral Pro and the other brands, I deduced that my silica and phosphate problem is the fault of the salt. Coralife tested much better, so I am changing a couple of gallons per day to get more Coralife water in there.