Conider using a vortex style settling tank which is fed by a series of bottem drains. The settling tank can be burried at the same depth as the pond and will filter out your solid waste before it reaches your bio filter. Do a google for vortex settling.
Just curious...... where can i get a pond like that? even though i have a 1300g indoor pond, i think it be perfect for my stingrays.
You can use a pressurized filter also for a pond it can be out of the water up or below the pond it dosen't mater. I have a 2200g powerhead/filter hooked up to a 800g Pressurized pond filter.(you need at least two clamps and a little bit of silicone to seal the connection to and from the hoes connections) you can also use a inwater pond filter.(the filter stays in the water like a filtered powerhead.) I got my 800g filter for about 60bucks, it was 75bucks at lowes. they are having a sale around here due to season changes.
I'm turning my 1300g pond into a diy tank with glass. here is a picx....
It is all in my bed room... It's under Reconstruction for now i will post pictures when i'm done.