sick sailfin tang

[jonpowell21]

For about 4 weeks now my sailfin tang has progressively had its fins deteriorate (extremely blunted "sail")as well as the appearance of discoloring markings around its face and eyes. From my readings, it sounds like "hole in head" disease which I thought was a nutritional problem. She eats like a horse and I've been feeding her spirulina flakes supplemented with Zoe and Zoecon as well as brine shrimp and some meatier shrimp, mussels, squid etc.
My water quality has not been a problem. In addition, I have a blue headed wrasse that has begun to show similar discoloration around his eyes as well.
Any ideas as to what is the cause and what I can do to improve things? any help would be greatly appreciated. Thanks in advance.
my set up: 135 gal oceanic FOWLR x13 months
fish: percula clown, stars and stripes puffer, sailfin tang, two small blue damsels, blue headed wrasse, diamond watchman goby, snowflake eel

 

[sebae0]

sometimes current from an electrical device can cause stress on your fish and they can develope lateral line disease from this. check your water for a stray current, do water test and post them on the board. also i'm no expert but maybe beth will get to this one and help you out. hth

 

[beth]

What are your nitrate and phosphate readings? What type of filtration are you using? How long have you had these fish? If you have had them for a long time and this just started developing, what has happened in your tank that may have inititated this problem? How much "grazing" opportunities does the tang have in your tank?

 

[jonpowell21]

I just checked my levels and the nitrates were high at 20-40ppm. I'm preparing a 20 gallon water change as I write this. I don't have phosphate level testing equipment.
I have a CPR 194 biofilter with protein skimmer, an Ocean Clear 325 canister filter and a 25 Watt UV sterilizer in the "system." The sailfin tang was one of the first inhabitants with the puffer (12 months). I can't think of anything that has happened to the tank in the last several months--no deaths or new acquistions.
There is plenty of live rock with algae growth for the tang, if that is what you mean by "grazing opportunity."
Thanks again for your previous input.
--a rookie to the fascinating world of marine fish keeping

 

[beth]

As I guessed. I have found that high nitrates equals problems for tangs resulting in HLLE. What type of substrate do have? What medica do you have in your canister, and what is your matenance schedule for the canister? The canister as a primary filter could be the problem as these systems can become "nitrate factories".
Do you have a grounding probe? Do you have PHs in the tank?

 

[nazarma]

what is a grounding prob

 

[beth]

http://www.aquarium.net/996/996_5.shtml

 

[jonpowell21]

My substrate is crushed coral. The substrate in my canister filter is charcoal and I change it every 3 months and change the filter in the canister every 4 months. I do not have a grounding probe but will soon get one. What are "PHs"?
thanks

 

[beth]

Originally posted by jonpowell21
My substrate is crushed coral. The substrate in my canister filter is charcoal and I change it every 3 months and change the filter in the canister every 4 months.
Hmm...was guessing that too. The combination of cc and the canister results in high nitrate. Do yourself and your tang a favor and seriously consider a redesign here. Is it possible that you can go DSB and get rid of the canister altogether. A good skimmer, power heads [PHs], LR and sand will, I bet you, clear up your tang woos.