Turn overflows into wet/dry filters?

[SeanCJ]

I'm looking at a 900 gallon bowfront tank that is 116" long by 48" tall and has two large overflows that are 14" wide and 8" deep. This will be a freshwater community tank, with several discus, large schools of rainbow fish or giant danios, and 300 plus neon green tetras.
The problem is that the custom steel stand that comes with this large tank is only 18 or so inches tall. So, there is not enough room for a sump underneath it. The previous owner had all filtration behind the tank in a separate room, which I can't do.
Do you guys see any reason why I can't turn both the overflow boxes into very tall wet/dry filters? Create a small durso stand pipe to keep about 8 inches of water in the bottom, place an eggcrate shelf above that, then fill them both with bio balls and top them off with some filter pads for mechanical filtration. The return pump would basically be run inline underneath the tank.
Would these two 'overflow wet/dry filters' along with two or three FX5 canister filters be enough to handle this size tank with above mentioned bioload?
The tank is drilled for a closed loop, so I can run that for extra flow.
What do you guys think?

 

[Pharaoh]

I would think that it should be enough.

 

[Wet Whiskers]

We had to set something up similar in design except in a 5 gallon bucket after a tank broke in the middle of the night. That will work fairly well for filtration puposes, howere, I do have two recomendations. 1) Put a layer of very loose weave filter floss as the top pad and then increase the finess of the pad with each layer. That will definitely help with clogging. 2) Nothing you do will gurantee that you won't get a clog at some point. I would HIGHLY recommend putting an overflow pipe that runs from just above the top of the filter pads and normal water line all the way to the bottom. Just put a t at the end of the pipe and cap off the very bottom to make sure it can sit completely on the bottom with no obstructions. This will keep you from potentially flooding your place, burning up pumps, or killing off fish due to lack over water turn over. G/L
on iPhone. Sorry for any spelling or grammar problems.

 

[SeanCJ]

Thanks Wet Wiskers for the advice! The extra drain pipe is a great idea!

 

[Wet Whiskers]

Thanks Wet Wiskers for the advice! The extra drain pipe is a great idea!

You're welcome. That's we all come here. Not too many places you could go that could answer these kinds of questions. Good thing for MFK. I'm guessing its saved a lot of fish, a lot of floors, and a lot of equipment, but can't say the same thing for money. It just opens your eyes to new cool things that you "JUST HAVE TO HAVE!" Good news for you, this round of advice comes at the cost of a little bit of PVC.

 

[cchhcc]

Running a pump inline would create a siphon. You'd be sucking air eventually.

You need some sort of a small sump.