Congratualtions on your pond build. I think you first need to decide what the focus of the pond will be bofre you try to figure out what to stock it with. If fish will be the focus, then most people choose Koi. Your pond will need to be at least 4 ft. deep for Koi, with a 1ft shelf for marginal potted plants. Some ponds for Koi actually incorporate the plants with the bio filter in a seperate area since Koi will destroy your plants.
If the pond and plants will be the focus, then you should stock your pond with fancy Shubunkin (Japanese for Poor Mans Koi) or another variety of Goldfish. For Shubunkin, your pond will only need to be 2 ft. deep in the deepest section with a 1ft shelf for marginal plants. Shubunkin will not destroy your plants so you can stock your pond with many beautiful plants.
If your pond will be in a full sun location, you want to choose plants to help cover 70% of the surface area of the water so the fish have a place to hide from the sun. The plants will also help control algae formation in full sun locations.
Our pond is about 2500 gallons and it is stocked with Shubunkin and a variety of plants. Our filtration is a 100 gallon biofilter at the top of the waterfall.
Check out the webiste for The Waters Edge in Lawrence, Kansas. Sue and Deb have tons of information for building and maintaing ponds.
Good Luck!
Im mainly worried about filtration, Id like to have atleast a 1000 pond and would like to have a good amount of filtration. Itll be partially buried, partially above ground. Just wanted to here some good inexpensive ideas for good filtration. Thanks