Water Gardening: Post Dramatic Pond Disorder, 1 by BogweedBuck

BogweedBuck wrote:
The "Bio Filter" ...

This was basically an unused 5 gallon painters bucket with a tight lid that I purchased at a local hardware store. Here's where you can some fun being creative. In short, you need to provide a leak free way of pushing a large volume of water through this bucket. This set-up requires one to make use of gravity to get the water back into the pond. Therefore, water entered the top of the bucket and exited towards the bottom.

1) I drilled a hole in the middle of the lid large enough where I had to use a little force to get a 3/4" a 90 degree insert elbow fitting pushed in.

One of these guys ... (the threaded part is pushed into the lid, the "barbed" end is where it inserts into your hosing)