I have a question about QT tanks.

[Cali]

I've heard several times that you should QT your new fish before you put them into your established tank EVEN IF you KNOW the new fish are healthy.

The reasoning behind this has always been because (at the very least) you don't want to expose your new fish to any pathogens your established tank may have.


This makes good sense to me, but then I was thinking:


If your QT tank is being maintained by one of your regular fish, isn't it just as likely that your new fish will be subjected to any pathogens in your QT tank? It just seems like you will have the same problem in QT as you would in your established tank. Surely, there are pathogens in both tanks...right?


Can someone clarify?

Thanks,

 

[The-Wolf]

The reasoning behind this has always been because (at the very least) you don't want to expose your new fish to any pathogens your established tank may have.
,

I think its the other way round
You don't want to introduce pathogens to your existing tank.

 

[clutterydrawer]

I was under the impression that the QT tank was to observe the new fish to see if it developed any disease in the first few weeks, and so that if it did, you could treat just that fish rather than your main tank.

 

[Cali]

Thanks danio and cd. I was under the impression that, in addition to protecting the established fish from the new fish diseases, we are protecting the new fish from the established fish pathogens when QTing.


I dunno.

 

[FishDan]

That's correct, you are protecting the established fish. There shouldn't be any but the normal "background" pathogens in your established tank. It is the new fish that are going to be weaker (due to stress of transport, etc) than your established fish. Also, it is mostly impossible to know that your new fish are certainly without pathogen(s). They may have something but may not be exhibiting sympoms yet. A well maintained QTank shouldn't really be running all the time, especially if you have treated a disease in the tank at some point. Unless you add fish regularly, it is best to set up this tank only when adding new fish. Keep some filter media in one of your established tanks so it will be ready to go when you want to add new fish. After your new fish are deemed healthy enough to be moved to your main tank, break down and clean the QTank, especially if you did treat for some disease. Otherwise you will just infect other fish you put in the tank.

\Dan

 

[Cali]

That's correct, you are protecting the established fish. There shouldn't be any but the normal "background" pathogens in your established tank. It is the new fish that are going to be weaker (due to stress of transport, etc) than your established fish. Also, it is mostly impossible to know that your new fish are certainly without pathogen(s). They may have something but may not be exhibiting sympoms yet. A well maintained QTank shouldn't really be running all the time, especially if you have treated a disease in the tank at some point. Unless you add fish regularly, it is best to set up this tank only when adding new fish. Keep some filter media in one of your established tanks so it will be ready to go when you want to add new fish. After your new fish are deemed healthy enough to be moved to your main tank, break down and clean the QTank, especially if you did treat for some disease. Otherwise you will just infect other fish you put in the tank.

\Dan

Makes perfect sense... If I'm understanding, it seems that if the new fish are weak (from transport etc), they are susceptible to even the healthy "normal" pathogens that may be in your established tank. Yeah, I was wondering because I ordered angelfish from an internet supplier that is known for his quality fish... so, I was pretty confident that the fish I received were healthy. I QTd them anyway because I had heard that they (the new fish) need to be protected from the pathogens in an established tank....outside of the normal QTing for potential diseases.

What you said about breaking down the QT tank makes sense, too. I heard lots of folks say that you should keep a spare tank running for QT and hospital tank purposes. I like the idea of keeping an extra filter running in my established tank instead.

thanks!