montipora turned brown

[Kremis]

Hey all, I have 2 rainbow montipora colonies that browned over the last 2 days. They used to be bright orange/yellow then they turned brown. I believe it has something to do with a chemiclean treatment I just did (turned off skimmer and removed carbon) I have 2 colonies in different spots. One is in the middle of the tank and is like 8x5, and another one is probably 3x3 at the top of the tank. Both browned, so I am assuming its something with the water. Probably nutrients, because of the skimmer being off? The tank is a heavy stocked 180 gallon.

[lilyost4290]

well, as you said, it could be nutrients in the water. What are your params?

[McPuff]

Also guessing nutrients. The chemi clean shouldn't affect the corals directly but the side effects of treatment may. Build-up of nutrients is certainly a possibility. I'm assuming that you're having an issue with cyano. Gotta get the nutrients under control for sure. Do you have any nutrient export at the moment? I'd suggest going with GFO and some type of chaeto/ulva/etc. Do you have a sand bed? If so, how deep and is it regularly stirred by you or small organisms? Try a sand sifting star... you MAY be able to get away with two in a 180. They do a terrific job.

[gprdypoo04]

Your nutrients would have to be fairly high. My montipora are fine with the exception of one which has been the same as when I bought it long ago. My nutrients are higher than I like but not having any problems otherwise. Unless you went suddenly from low to higher nutrients ??????