Using lime to increase alkalinity - when is enough too much?

[ajdelange]

At the moment the presumption is that if your lime is 50% effective that is because the rest of it is CaCO3 which only reacts slowly. If this thesis is correct then yes, you would end up with twice the alkalinity you need with the first increment available immediately and the second or part thereof released over a longer time period.

 

[CadiBrewer]

At the moment the presumption is that if your lime is 50% effective that is because the rest of it is CaCO3 which only reacts slowly. If this thesis is correct then yes, you would end up with twice the alkalinity you need with the first increment available immediately and the second or part thereof released over a longer time period.

The easy solution seems for me to use lime that is 100% effective. Not sure what my first bag started at, but it wasn't stored well (the bag it came in didn't seal well from the outset), and after a year, it ended up at 50% effective. My second buy (reef grade Kalkwasser in a screw top container) started out at 50% effective when I opened it. Where does one procure better lime?