Some of my other SPS is doing fine but for some reason my blue tip acro and a couple others are turning quite brown.
Tank: 40 breeder
Flow: Tunze 6025 x2 (modded)
Lighting: DIY Cree LED (~160w)
Nitrate: < 1
Phosphate: Undetectable on salifert test (~ < .03)
Alk : 11
Running GFO / Activated carbon in reactor as well.
Growth isn't an issue, just having some alarming browning. Note that I have 3 frags of the same coral and they are all at different depths, all 3 browning. Wondering if anyone has some ideas.