star polyp looks burned?

[wozza]

well as the title suggests a few of the stars on my colony of brown star polyps have turned black, this happened about 4 days ago and it has gone down slightly since then, it only appears on about 10 heads or so out of 200.
I think there may be a couple of things that have caused this, what do you think?

1-my nitrates were at 30ppm
2-i don’t know what flow they like but, they were in a low flow part of the tank
3-to much light I have 3x39w T8’s one is actinic, there are about 4inches off the surface and the coral is about 9inches below the surface of the water.

What you reckon?
Cheers James

[mungus728]

My guess would be the high nitrates. I have seen it before and it is usually because of water quality issues. I don't think it is to much lighting because I have seen them flourish under 400w metal halides.

JMO
Brian

[wozza]

yep ok cheers thats sounds right, i used to use tap water for my water changes and the nitrates in there are at 10ppm before i even but it in my tank. but ive started useing r/o water now so hopefully that will sort things out.

cheers james

[Reefland]

What are the other corals closest to this one?

[wozza]

there is i a 2 inch beadlet anemonie about 6 inches away and thats it!

[Reefland]

I am not sure what kind of Anemone that is but I wouldn't rule out the possibility of an anemone sting.