This drain is for the bottom drain install that is done after the pond is complete, not for a new install where the plumbing is done under the structure of the pond. The plumbing for this bottom drain will be visible inside the pond. The connection point is a Glue in 2″ PVC coupler. Weighing in at around 30 LBS this drain will not float or be moved by fish.
The bottom drain sits about 1/2″ to 3/4″ off the bottom of the pond to allow for leaves and other debris to be sucked up by the suction line. It is possible that fish that are less than 8″ can be sucked in. If you have smaller fish, you may use a hack saw to make the legs shorter. In our experience, even at the standard drain cover height, healthy 5″ or larger fish, feel the current from the drain and swim away.