Aqua Art Bottom Drain
Many times after someone installs a pond, the owner regrets that he or she did not install a bottom drain. What happens over time is that a lot of debris settles on the bottom and as the fish move around they stir it up so the water is never truly clear even though a skimmer and filter is installed.
With a real bottom drain that is constantly moving water from the lowest level of the pond all the debris that would normally settle in this low place is pulled to a filter which is usually outside the pond. Once the debris is outside the pond it is easier to dispose of it.
Aqua Art has made a very effective bottom drain that allows one to place it on the liner on the bottom of the pond and draw debris out of the pond. Below is a photo. Note the four flaps or legs that extend from the drain. Placing four bricks on these holds it down. Also not that various size flexible PVC can be attached to the bottom drain. The blue masking tape on the top of the drain just has some notes on it about maker and cost.