TetraPond has two types of bottom drains regular and vacuum style. They should be installed at the deepest point of pond.
Both are superbly engineered device encourages debris and waste to flow into a circular collection chamber. the regular bottom drain carries debris away underground via standard 3" PVC pipe (not included) to a disposal area away from the pond. Its dome-like shape is designed to force debris and waste to flow into a collection area while preventing debris from settling on top of the drain or away from the collecting vents. In seconds, accumulated debris is permanently removed.
The Vacuum drain can be installed without cutting the liner . Simpley connect 2" flex PVC pipe to the drain and remove waste and debris from pond bottom.
Most pondkeepers know that the best way to ensure clear pond water is with an ultraviolet sterilizer. Some often overlooked factors are what to do when the UV light is not doing the job anymore. Usually, this is a simple as an old lamp. Depending on the brand, UV lamps should generally be replaced about every 12-15 months of use.