I'm not sure Ibassfsh. I was under the impression that once you initially get a calcium reactor online, you then dial it in to whatever calcium level you want?
Since the effluent has a higher calcium content than what is in the tank, would that not increase the level? I know that my magnesium is a little low and I understand that can make it hard to maintain calcium and hardness, but don't fully understand the chemical reaction that causes this. It might be that what I really need to do is to increase my magnesium a little and then perhaps my calcium level will fall into place.
It will cost me a fortune to raise the Mg level of 400g of water using those little bottles from the lfs. I'm investigating some of the alternatives that have been suggested here and also looking into forcing an increase in the calcium level using calcium chloride and/or baking soda.
The bottom line is that I'm looking for the most economic solution to maintaining Mg and Calc, taking into account that I already have a calc and kalk reactor which apparently aren't up to the task by themselves. The easiest might be to score a bucket of Oceanic salt and use that to boost my Mg during water changes, but nobody around here seems to carry it.