Anne

Anne,

I would strongly suggest never adding the cleaner wrasse back to the tank with the cowfish.  I would also suggest that you take the wrasse back to the LFS as they do not do well long term in captivity.

What substrate do you have in the tank with the long horn cow fish?

Best of luck,

I got the wrasse from someone who was closing out her tank, and I am quarantining him now so that I can give him to someone else without passing on possible ich.  Or is that not necessary with a wrasse?

The substrate, apart from the live rock, is a shallow white gravel layer, perhaps an inch thick in spots.

The cowfish seems improved, and the eyespots are not as dense.  One of the tangs has a new red raised spot on the anterior part of the dorsal fin.

Anne

I applaud your effort/concern for helping your fish.

The wrasse absolutely has to be quarantined.  Anything that is wet - rock, sand, inverts, corals, algae, fish, etc can carry parasites and bacteria.

The red spot on the tang could be a bacterial infection.  You really should consider treating the tang in a separate quarantine tank with hyposalinity and an antibiotic - Maracyn 2, kanamycin or nitrofurazone. 

Make sure you are monitoring your water parameters at least daily as fluctuations in pH or ammonia can cause redness.  Hyposalinity in your display system can kill off the microfauna on the rock/substrate.  Hyposalinity can affect your pH so you may need to add buffer in order to stabilize the pH and decrease stress on the fish.

The problem, which you have already experienced, is it is difficult and sometimes impossible to treat fish in the display system.  The substrate and rock will absorb and leach medications.  This not only destroys the nitrification capabilities but makes getting a therapeutic level to treat a fish impossible.

The recurring problem is the display system obviously has ich - you are/will be treating with hyposalinity for at least 8 weeks.  There is an opportunistic bacteria in the system which when the fish are stressed (ich infestation and recent/past water condition issues) they become infected with the bacteria.  You had treated last month with antibiotics in the main display system.  While the fish improved, the bacteria is still present and may have developed a resistance to the antibiotic that you used since the rock & substrate didn't allow the antibiotic to achieve a level needed to wipe out the bacteria.  You might consider removing the substrate and  doing large (50 %) water changes every couple days for a week.  Make sure you keep the salinity low.  This will hopefully decrease the bacteria and parasite count.

I know you added a UV, in order to improve efficiency make sure the water entering the sterilizer is prefiltered and the flow rate is within the manufacturer's specifications/recommendations.  The UV will now cure the problem, but it can help decrease the number of pathogens.

Beta glucan, garlic and vitamins are a must in this situation.  These fish have been under ongoing stress for several weeks.  Their immune systems are compromised and they need any and everything they can get to help them.

Best of luck,

I have cut/pasted this thread and placed it in the "Disease, health and wellness" by Kelly Jedlicki forum (me   ) under the thread entitled "white spots".

If you could post updates and progress in that forum - that would be great.

Again, best of luck.  Look forward to updates.

-Amy-

-Amy-