Scopas tang is sick, can you help me identify symptoms?

[Tim Reed]

I have my tang in a 55 gal with two clowns, a goby, and a fox face. The tank is about 8 mo old, no changes except temp has gone from 78-80 down to 74-76. He has a great appetite, but he suddenly darts across the tank like he has a bug in his brain then comes to a "raising" halt like a horse. Then he does it again and he is breathing hard. About 4 weeks ago I put in a manderin (less than an inch long) and I think it died ($4 because he was very very skinny and not expected to live). He lived 2 weeks and disappeared (bristle worm food I guess). I did 20 gal water change last weekend. Recently I decreased their feeding to twice a day to control nitrate problems. Halide lights 6 hrs, blue actinic 9hrs, ammonia 0, nitrite 0, ph good, specific gravity good. Possibilities: manderin had flukes or something, manderin is poluting tank (but he was too small), I have a wet/dry, and then a 2'x1'x1' refugium with calerpa (ms?), cleaned the filters but then rinsed filters in R/O water. Salt cust may have dropped in the tank maybe burning his membranes a little. He seems like he tries to rub the glass to rub something off. I have a new cleaner shrimp (2 weeks) but he is to new and small to start cleaning fish. That is about it... Thanks for replies.

 

[Shelby1317]

On the temp.....how long is the adjustment from 80-to 74????

 

[Tim Reed]

In the summer it's around 80 but as of 2 weeks ago it has been hanging around 74

 

[samurai9]

take the wet-dry media out if you haven't already done so-will help with nitrate problem

 

[Mac1]

Could be feeling crowded. I noticed my tangs used to pace in my 55, and the Sailfin's starting to do it again in my 90 (honey, time for a new tank!). The rubbing sounds like Ich is starting. Make sure you've got food in an algae clip for the little guy. It could just be boredom too... Not much to do in a 4x1.5 foot cube, when you're used to having miles of ocean to swim around in.

- Mac