I wouldn't. You really want to be able to easily tear the
QT down and clean/disinfect it. I would probably just have a decent
HOB filter and perhaps a couple of pieces of
PVC pipe for the inhabitant to hide in. You'll have to be very careful using this tank even as a
QT due to the small volume of water. Things can go wrong very quickly in a 5g tank. I'm not trying to discourage you though...a
QT tank is very important and, as long as you check the water parameters every day, I think you'll be fine with it.
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