Calcium and dKh dropping rapidly!

[xenon]

With limited corals, you can get away with water changes to maintain cal/alk/mag but there comes a time when corals consume faster than you can replenish with water changes so its time to start dosing.

It's much cheaper to dose what your corals consume, rather than doing bigger water changes.

Your water may be too clean for LPS. That is my problem also. You will need to target feed your LPS if you want them to grow.

Make sure you never let alk drop bellow 6.5dKH. That is when bad things happen to SPS. We keep our system stable @ 7.5dKH.