i have recently come up with a simple design for a very large canister filter for those of us with seriously overstocked tanks. i havent made the first one yet, have to wait for payday, but if any of you are interested in the parts and assembly instructions, i will be making it available as soon as i get all of the oopses worked out of it. total cost to build will be about 100$. the design is extremely simple (maybe that is relative to your own craftiness though) and anyone can make it. say hello to higher bio-load for less money.