The big tank is over stocked, ideally i would like to lose the pangasius cat and the severum from there as they were never intended to be there in the first place, that would bring the stocking down to 5 rays, the big catfish, flag tail, arowana, 2 peacock bass and the fire eel, 11 fish in 205 gallons of water isnt so bad. The tank is filtered with two Eheim 2217's filled with efi substrat pro and a 30 gallon pond filter box filled with plastic rings situated above the tank served by a 1500 LPH pond pump, the return then flows into a home made trickle tower with floss and sponges before it drops into the tank, the pond filter alone is rated for a 600 gallon pond and the Eheims will do 150 gallons each so there is LOTS of biological filtration going on. Weekly 40% water changes take care of the nitrate and dissolved organics.
Hopefully soon i will be able to afford the 400 gallon tank ive been promising myself for the last year which will give them all pleanty of room.
Vancouver, the ID shark (pangasius cat) belongs to a friend of mine who has had it a couple of years, it outgrew their old tank and needed a temporary home until they got their new larger tank installed. They have the new tank now but decided they didnt want the catfish back although they have now said they will take it back if i cant find another suitable home for it. Its about 13-14 inches at the moment.