SPS STNing from the center? (w/ pics)

[ryanuy]

Hi guys! I have a 155g DT with 80g sump. I run 5 AI sol blues, ATB deluxe 10.5 and 4 MP40s in the DT for flow. I also use BP in a reef octo reactor and i have a chiller to keep the temp steady at 25degC.

Its a mixed reef and i keep LPS, SPS, and zoas. For some strange reason, the milleporas(i have 3 colonies) and one of my acros have started to STN or bleach out from the center outward. The bases are totally fine its really just the center part. These SPS have been with me for at least a year and i have grown them out from small frags so i dont really understand what happened. The other SPS in the tank all seem to be doing fine. The LPS and zoas are also doing ok.

Salinity is stable at 1.025. P04 is 0. Nitrate, nitrite, ammonia all 0. Cal is stable at 450. Alk in between 7-8. Im quite sure of these numbers since i test quite regularly.

I also use a bit of zeo but not the whole system. I only use coral snow, pohls xtra, and amino acids to help the corals grow faster.

Please help!

As you can see with this mille, the tips are all ok. Its just the center which has a problem.

As you can see with this mille, the tips are all ok. Its just the center which has a problem.
http://i934.photobucket.com/albums/ad181/ryanini/IMG_0479.jpg



Its the same case with this acro as well.
http://i934.photobucket.com/albums/...obucket.com/albums/ad181/ryanini/IMG_0479.jpg

 

[NeverlosT]

My first guess is flow. Usually that only happens on my colonies not receiving enough flow to the inner branches. Crank up those vortechs maybe?

 

[MattL22]

Flow could Be it might.be time to trim it up a bit over heard of sps colonies growing so big that flow and light can't be meet and they start dying!!
Good luck! Did u grow that from a frag??