Salt mixes vary on importance, be it high calcium or alk
. Each has their own. I get whatever is on sale. I personally didn't have a good run with Red Sea Pro and it ended up with a cyano
outbreak, which is something I read about some others having this issue as well at the time. Not sure why or if the salt was to blame, but there is some relation there.
In terms of absorbing alk
easier than calcium, not really. Soft corals will use alk
but not calcium for example. It just isn't that easy of an answer.
You are doing a hefty water change, so that is good. This should be replenishing things as best possible, but if the corals are in there using them up faster than you can replenish by water changes then you will need to continue dosing.