What does this mean? I've seen my other fish do it and usually a few days later they kick the bucket. I placed two black sebaes in with a BTA. They both took to the BTA within 30 minutes fighting back and forth inside the anem. Then i got up in the middle of the night to check on things and one is swimming lazily near the top of the water and the other is still living in the BTA. What can i do?