hey i need with somtihng off topic i can't post a new thread to ask a question. also i keep geting pics of tanks that arn't mine in my gallery please help me.
That's better, but I would use the first drum completely as mechanical and have two additonal tanks as bio. W/ the first drum a combo I think you're always going to be cleaning it. I would also put drains and valves on the bottoms of each barrel for flushing and cleaning. 3" shower drains can be used. Check out www.koiphen.com in the pond/filtration section. There are a ton of DIY filters. Check out the Kent Wallace's seciton for his upflow sand/gravel filter. There are links to converting pool sand filters to low head bead filters for polishing. One thing I learned reading over there is you cannot have too much filtration. Of course, it's space dependent.
Any more quesitons, fire away. I'm not an expert, but I have read a lot of stuff on pond filtration in the last 18 months.