Jim, I forgot to ask, are you cleaning the filter cartridge? or replacing it?
A light rinse with dechlorinated water or tank water is all maintenence the filter floss needs at this point. I would Not replace the cartridge because then you are losing accumulated beneficial bacteria which forms on the media and consumes the ammonia waste produced by the livestock
Also, your tank is definitely not Underfilterd, which is why the powerhead is also redundant. There is plenty of water movement, you just need a good bacteria colony to get established.