Weighted Suction Drain Retro (with Aerator)The Weighted Suction Dome Range was developed for customers who have a new or existing pond but want the same great benefits that a bottom drain gives you, without having to rebuild your pond. Weighted Suction Domes are a great device and once connected will greatly improve the water circulation around any pond. This improved water circulation helps remove suspended particles and debris from the bottom of your pond, resulting in reduced maintenance.