Today I came home and went to check on my fish. When I came across Peewee's tank I thought, "Where's Peewee?" I searched the tank and saw his head stuck between the plastic water bottle half filter baffle and the filter, his body going up and down with the current. I honestly thought he was dead. I spent the next couple of minutes thinking about how he didn't get the long life he deserved, not bothering to turn the filter off because I thought he was gone. I thought, "May as well take him out now," and turned the filter off. I looked closer and thought that I saw a slight breathing coming from him, so I lifted up the baffle and he swam right out. I was so relieved he was alive and swimming.
He seemed a bit distressed at first but he's acting fine now. The only physical appearance differance is an orange streak on his bottom fin (forgot what this one's called, anal maybe?) What's worrying me is I have no idea how long he was in there for. Just now I looked over to Peewee's tank to check up on him and he was swimming down between the baffle and the filter (turned off) once again (there's a gap because the outflow bit sticks out). I think maybe he has a strong desire to explore the most tight, unreachable places in the tank

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The filter's out of the tank now and I'm wondering if it should stay that way. Is it okay to have a 5 gallon unfiltered tank with regular water changes?