I've been asked a few times for a "parts list" for this build. Aside from choosing the containers you want to use, along with whatever filter media is best for your pond, below is the short list of actual "parts" that took me a bit to decide on:

The pump (VERY long lasting and hard working ...STILL): http://amzn.to/2fVPRlD
2" pipe attachment to container (no glue required): http://amzn.to/2o4yrdO
1" pipe attachment to container (no glue required): http://amzn.to/2pD9G8G
1" PVC valve(I only needed two of these in the end): http://amzn.to/2pD9WEp

A month ago my pond was such a mess! It was a green pea soup. The water quality had diminished so much that I was unable to see an inch into the water. It happened this way because I believe in a chemical free environment and at the same time did not have an adequate filter. This DIY trash can filter is super cheap to build and easy too! The best part is that is WORKS!