My Craigslist Pond Plan

My Craigslist Pond Plan:
I want a pond. We have an unused pool. You can see where this is going.

The plan is to only get things off Craigslist or use what we have lying around. I realize this is going to take months, both to assemble the parts and to get the water running smoothly and grossness-free, but I apparently need a hobby (something I am in complete control of), so this should be it. I've really taken a liking to our turtle and think that he'd truly enjoy the snot out of a 6000 gallon pond.

After extensive research and writing things and diagramming like someone on caffeine with a pencil, I have come to the conclusion that I need these things:

First:
2 100 gallon containers (round trash cans or similar)
2 1500+ GPH pumps
PVC (which I have a lot of, actually; I just have to find it)
PVC sealant / glue (have this too but might not have enough)
Filter material (which may be the only thing I buy new)

Second:
Floating plants (jumbo hyacinth and frogbit are my top choices)
Planted plants (water lily and some ferny things)
Shade plants (big leaves, can be in-water or side-planted)

I've measured our pool and I'm only going to fill it three feet up. This would reach the second stair (barely) and it would allow for two basking areas for the turtle since we also have a side stair / ledge about that high. And only having three feet of water would allow a great slow rise for shallow plants, plantable plants, and submerged plants to branch out in stages without cramming everything into one area.

Once I get the pumps running, the filters built, and the water smooth and clean for a while, I'll add in the plants. Then I'll ensure the pH and temperature are acceptable for a time, and ... maybe next year Mr Timmy Bonk will get a new home. ... I'll probably stock it with Koi first, though, so they'll get too big for him to eat.