they are still sick catfish's,he still amazes me!!
I always ask my self:
will he eat three chickens or five?hmm this is a question!! =P
not really but it always amazes me how much he can eat.
Drcamp how big is your red tail catfish?if he is under 10" it should be easy to get rid of it,just keep your water clean and healthy,buy more bio rings,in my opinion biological filtration is most important.
make sure that you have low level ammonia!!
and also make sure that your aquarium has enough air!!
air is very important to have healthy fish's and also air is very good for bacteria's in a filters,try to get an koi overhead filter,they cost about £30 in uk,I have one of them connected to my fluval's 405 and it works great.