Yellow Tang's not doing well in QT (Chloroquine Phosphate)

[Spar]

I purchased 5 small/medium yellow tangs and a sailfin tang. I am keeping them in a 29g for QT. They were all doing great, eating well, for the first 5 days before adding chemical. I then added 60mg/g of Chloroquine Phosphate (CP), and 2 of them began looking lethargic and stopped eating within 3 days, both died today (5 days in). There has been no noticeable fighting, nor any spine wounds to show for it.

Any chance this is related to the CP? Do YT's do better with Copper Power? Or is it more likely that they were just unhealthy?

Of the remaining YT's, 1 is really small and is looking thin even though is continuing to eat. The other 2 look great. The sailfin also looks great.

Thoughts?

 

[rkpetersen]

Chloroquine shouldn't be a problem for any tang but P. hepatus.
That said, I've experienced strange deaths of other fish in CP that I wondered about.

One thing to consider is that CP adds a sizable amount of phosphate to the tank.
Levels can actually get quite high, especially if you don't do a complete water change between treatments.
Most fish of course aren't that susceptible to phosphate, but can be harmed if levels get really high, in the 100 ppm range.

Copper Power, surprisingly, also contains phosphate, so this all may be a red herring.

Any chance that there was an ammonia spike? Fair number of fish to add all at once to a QT that size.

 

[Spar]

Re: Ammonia, i dose Prime every day or two, and also do 75% WCs every 4-5 days. So shouldn’t have experienced ammonia. There wasn’t any ammonia burn marks nor heavy breathing.