Poly filter pure turning bright blue

[offroadr]

I bought a used 20g tank as a QT tank, I have lost several damsels in the tank and not sure why. I am now curious if its from the tank. I scrub it with vinegar and water before use.

I put a portion of a poly filter pad in the hob filter I have and in a week it turned bright blue. That says copper, I have not added a medicine to the tank so it must have alot in the silicone?

I know it shouldn't be the copper that killed the damsels.

I am considering pitching the tank and getting a new one at this point.

[RickReef28]

I would just keep the tank running and continue to use the polyfilter until it takes out everything. The point of a QT tank is to medicate so the damsels are not dying of trace copper in the water. The damsels are probably dying of ammonia. QT's have no sand or rock in them and they depend on only filtering to make sure there is no ammonia and the tank is being cycled right. Dont cycle tanks with damsels. all you have to do is run the tank and ghost feed it till your params are all stable. just my .02

[offroadr]

Yes I agree, I was very surprised to see the color of the poly.

I need to cycle more. I saw .2 ammonia yesterday