Hi I'm jason I'm building/ upgrading a koi pond for my dad. Were in mesa az where its 115 in summer . Right now its just a simple 6 ft diameter pond with koi simple filtr and pump some real nice lilipads and not much else. The goal is : It will have three levels, top level wher waterstarts ,cascade to second level biofilter thru plants, cascade to final pond area, approx fifteen ft wide , five foot back. Trying to keep in th 1000 to 1500 dollar range. Want to use 4000 gph pump, mechanical and bio filtration. Tryin to have abalance of keeping costs low as possible and simple design. Here's what I need to know. What's a good 4000gph pump that has agreat price. What's th cheapest and easiest way of doing mechanical and biofiltration and skimmer. How bout using those premade bio/mech filter tubs. How bout easy mainenance. I know imall over the place, just want to get the ballrolling. So first I think its best to know how I'm doing this so I can have a parts list for major components.. thanks for anyhelp