In theory, you'll get 800ppm ca and 112dkh per gallon from saturated limewater. In my system, I have about 140g system water and am using about 1.5g per day of saturated lime-water. So that would be 8.6ppm ca per day and 1.2 dkh per day. I'm sure I use a lot, but fairly sure I am not using this much. The reason for the discrepancy is likely that even though I am dosing as carefully as possible, there is still some wasted due to precipitation of calcium carbonate. So, you can start with these numbers, but you may need to adjust by testing, which you should do daily at first.