why is my coral turning brown?

[larkon8]

If you're dosing anything, check that too. Had a buddy overdose iodine and his corals turned toasty. Random but worth mentioning.

True story. Also, what's your temp stability like? Swings over 2 degrees can cause browning.

[porkbun]

Might wanna check for pests too. Flatworms or nudis can stress Zoas out. Grab a turkey baster and give them a gentle blast, see if anything flies off.