This will be different from tank to tank, depending on tank inhabitants, i.e. clams, stoney type corals, coraline algae will take up more than softies, i.e. Kenya Tree, Xenia's, etc. In my case I had a 180 gal. mixed reef, predominantly SPS, and I used 125mL ea. of Randy's recipe #1 per day, along with about 2 gal. of fully saturated lime water each day. This will vary with two part solutions too, since they may have different concentration levels.