Zoo colony with white coating - Help please!

[Paramedic]

First off, I checked on my tank and noticed some white coating on several of my polyps. The ones with the growth don't appear too bad off, but they are partially closed. The others have a rich green growth within the polyps and seem happy as can be. (Small zoo colony) There are three changes to the system that might or might not be causes.

 

First, I increased circulation significantly to the polyps (basically pointed the circulation pump at them rather than away). Second, the temp has (due to office AC) increased the range from 76.8-78.0 to a range of 76.4-79.0. Finally, I used after some research a small dose of maracyn to take care of some cyano. My ammonia prior to the maracyn was 0.25, but has been less than 0.05 since that time, so I don't think the problem is with ammonia.

 

I had to feed my brittle star and the polyps with the white coating were the first to reopen. I also redirected the current away from them to see if that might have something to do with it.

 

Any thoughts or suggestions?

 

Second, I wanted to find out if the temp range is still acceptable or if it's just way too wide to live with. I have a digital max/min thermometer and that range covers several days (not constantly up and down within that range) The general range is about 1-1.5 degrees.

 

Thanks for your help!

 

Jim

 

Tank:

5.5AGA, 2 X 13W CF 1 Blue Actinic, 1 10000K, Aquaclear 250 HOB filter, Micropump 250GPH for circ., 80W Visitherm heater. 6 lbs LS, 11 lbs LR, 3 margarita snails, 1 peppermint shrimp, 1 green brittle, 1 blue legged hermit, 1 emerald crab, small zoo colony.

Amm: trace (0.05), Nitrites 0, Nitrates 15, pH 8.2

[Paramedic]

Well, the white appears like it might have been bleaching and has diminished somewhat. I'm not sure if the cyano had anything to do with it (or the treatment) as I didn't see much cyano on the polyps themselves. I also turned the circulating pump away from them so they get an indirect current and that might have had as much if not more to do with it.

 

Any thoughts?

[tinyreef]

can you post a pic? i was trying to mentally picture what you described but you last post created a totally different picture. i was 1st thinking a growth on the polyps (like fungus) now i'm picturing bleach spotting. ???

 

a pic's worth a 1000 words.

[nanonut]

Yep, it's the circulation. It happened to me with my colt. I had it out of direct current, and it was nice and full and stretching out, and when I moved it into the current, it developed a white coating over the whole thing and it looked shiny. I moved it back to where I originally had it and it hasn't had that slime since. But sometime corals will do that and it's called slothing, or something to that effect. I have a spot in my tank where I just can't put anything. My frogspawn didn't like it there either.