Okay now just get good enough filtration. I use wave makers on my tank which I set on timers. Your catfish will probably hate it but if you set it on at only specific times, they should be okay for a few hours exercise. I direct my wave makers towards the filter intake so that all the dirt is instantly siphoned. My setup has a bubble wall at the entire back and a bubble tower in the center. I made the bubble wall by using 2 extra long air stones. The bubble tower is by using a 5" rounded air stone. It's mostly for aesthetics as aerators are known to contribute little to adding more dissolved oxygen into the water. I do better aeration by putting my canister returns into a trickle filter above my tank. The dropping water creates ripples on surface of the water that dissolves more oxygen. The very large trickle filter also adds more surface area for dissolved oxygen and additional water volume. This setup was put to the test the other day when my circuit breaker overloaded and the power is out for at least 3.5 hours. Not a single fish (of my many fish) is left gasping for breath when I woke up to the horror. I also think that over-aeration is good for the beneficial bacteria. For the canister filter, get at least 2-3 FX5's and stuff it with a lot of media. BTW, where is the arowana now in your list? It's only me but I would love either or both a giant gourami and a silver arowana in your tank. If you go this way, you need to remove at least a cat or two from your list and you're good to go.
