Jay Hemdal: every how long do you sterilize QT?

[Miami Reef]

If dosing Copper, metro, and prazi. Every how long do you sterilize tank to prevent bacteria from prematurely degrading medications?

 

[Jay Hemdal Verified Community Expert]

If dosing Copper, metro, and prazi. Every how long do you sterilize tank to prevent bacteria from prematurely degrading medications?

Of those drugs, I think that only Praziquantel is degraded by bacteria (and that can be a serious issue). Copper isn't degraded for sure. I don't think metronidazole is either as it is an antibiotic against some bacteria.

So - for praziquantel, bacteria grow in tanks over multiple treatments (like 3 or more). These bacteria consume prazi as a food source. With each prazi addition, they consume it faster, to the point where it doesn't last in the water long enough to have any benefit for the fish, or you have to add it at higher and higher doses. This is the root cause for "prazi resistant flukes" that you hear about - the flukes are resistant, just the bacteria has grown in that tank.

So - what to do? You can sterilize the empty QT with bleach and then restart it. However, you then must reestablish the biofilter before using the tank again for fish. However, if you can't do that, or if you don't have time to do that properly, I wouldn't sterilize the tank, and instead, consider hyposalinity to control flukes.

Jay