SPS outer "skin" sluffing off?

[erikharrison]

I was curious about this due to the fact that I will be adding sps to my new tank. I got a heck of a deal from TXTodd, awhile back on some slimer. The polyps would be fully extended, and there was a seio820 pretty much directed right at it. The "skin", if you will, started to bleach out on the underportions of the coral that didn't get light. The tips of the sps were pretty much right under the water on a 150w mh. It was first growing insanely, then it just flat out stopped. I would check the levels
-alk and they all registered correctly. Would a sudden change in alk cause this? I also was not testing for phosphates...

[Texreefer]

short answer yes.. long answer is we would probably need to see it and talk more about tank conditions and actual levels to be sure

[erikharrison]

all of the other levels were at 0. Pretty much always have been except for the beginning cycle.

[apedroza]

Did the underneath bleach out or just become pale in comparison to the topside? alot of the times, because the don't get as much light, the underside of the coral will not be as bright. If the polyps are still extending I wouldn't worry too much.

[erikharrison]

the underside bleached out, and spread. This all occured before my tank crashed. I had never tested the alk, so I am unsure as to the levels.

[Texreefer]

assuming its been in the tand a while and all other levels are normal.. its probably Alk

owning SPS + not testing for alk,cal,etc. = Disaster :)
Are you dosing for Alk or Cal,, if you are, you should get some test kits quick... if i cant test for it i don't add it

[jc]

I second that, texreefer. I'm sure it was the alk that killed my corals.

[hobogato]

i just dealt with that in my tank a bit also - my calcium reactor was malfunctioning and my alkalinity dropped to 1.8 meq/L (that is about 6 Dkh) :o i noticed recession at the bottom of the colonies and some of the tips. then, when i brought it back up to where i keep it (around 10Kkh) i had some tips burn. i am convinced that alkalinity is almost as important as salinity and temperature stability.

erik, if the tissue is peeling off, it is RTN, and you may be able to save the good parts by fragging them off.

[erikharrison]

I don't have any sps except for the monti that I got from you when I first setup (Mike).