Complete newbie here with a question about the sponge filter being used in a quarantine tank. I have a 29 gallon tank cycled by using Angels Plus active sponge filters. I purchased two. For the QT, I set up a very economical one, following a post I found here on fishlore, using a sterilite container and equipment that a I inherited, and placing one of the active sponge filters from the 29 gallon tank in it. My question is, after the quarantine period, assuming the quarantined fish is disease free and is placed in the community tank, can I safely put the sponge filter back in the community tank, or should it be discarded? I apologize if this question has been answered elsewhere. I searched the forum, but didn't see it.