Bringing in new fish QT question

[Lizalots]

Hi Reefers!

So we just successfully got 15 fish through a 30 day copper treatment in 3 different 20g QT tanks into our DT. No fish were exhibiting any ill symptoms and only lost 1 cardinal for apparent reason (my guess bullying by the larger one in the tank). 15/16 success rate for our first attempt! We also treated with GenCure in the water column and internally in their food during QT.

Ok, so now we are ready to buy new fish. Our tanks still have the “old” water in them which is still at 2ppm copper. I was planning on a 100% water change and then dosing to 1ppm copper (copper power), but not sterilizing the tanks as I don’t want to recycle them and wait for that to happen.

What’s my best course of action? Do
I have to sterilize to start over or can I just go ahead with the water change and keep on truckin’? If I had seen visible ich or something else I would of course sterilize, but I’m thinking I may be safe here?

 

[Qasimja]

me personally i would do a water change to lower copper power to 1.0 and not sterilize the QT if you dont need to

 

[Big G]

Copper doesn't degrade; but the General Cure does degrade and with it, there is the potential for the bio film to build some resistance to the Metronidazole and the praziquantel.

 

[Lizalots]

Copper doesn't degrade; but the General Cure does degrade and with it, there is the potential for the bio film to build some resistance to the Metronidazole and the praziquantel.

So it’s best to sterilize in between fish batches? Or every few batches?

 

[Big G]

With just copper it's ok to leave it running without tear down. But meds . . . that the problem, so I always tear down after using any medication. You want them to work as described when you need them to. There's "Prazi" resistant flukes in the system these days. . . lots of collectors, shippers, wholesalers, LFS continually dose prazi. So now it doesn't work sometimes and other measures are needed.