When Should I Add Corals to a Reef Tank?

Corals generally wait until after the tank cycles and often after the first fish or clean-up crew has been in for a few weeks. You want stable salinity, alkalinity that does not crash overnight, and nitrate under control — not necessarily zero, but predictable.

Brown diatoms on new rock usually fade within the first month or two. That is not the moment to load SPS; it is the moment to test consistently and finish your maintenance habit.

Place easy soft corals under moderate light and adjust based on polyp extension. Log alkalinity the week before and after adding corals in ReefDiary — a drop right after heavy coral additions tells you the system needs smaller steps or more frequent testing.