I'm working on getting a larger tank 600g for my basement.i had a idea about a home made filter.how effective are bio wheels?could you build a maze of say gutter material under the stand or something with a large bio wheel attached every foot or so inside so when water flows in it the wheels spin.and collects in holding tank and pumped back to tank? how effective could it be......any ideas? it could be built to house many wheels.any method to my madness?