I'm setting the pump to backwash and letting it drain, but when the swimming pool water level goes below the skimmers it stops pumping. Swimming pool main drains are much more than just that circle with all the little circles sitting at the bottom of your pool. CASE STUDY: The Option of Pools without 'Main Drains' Background . Learn from an expert on pool safety how you can make your pool entrapment-free and 100% safe from the hazard of main drains. Main drains on older pools are often attached to the skimmer lines back to the equipment. In a word, yes. Let's take a look at the language on swimming pool circulation and swimming pool drains for most of the United States from 1928: Consider installing dual main drains the next time the pool is resurfaced. Skimmers sit near a swimming pool's waterline, taking in water via gravity and letting it flow down to the filter. A vacuum plate will block the port in the skimmer that the main drain line is attached to and isolates the skimmer to provide the suction necessary to effectively vacuum the pool. And it’s important to fully understand what your swimming pool’s main drain does so that you can keep it working properly, and so that you can protect the swimmers in the pool from it. Main drain is essential for proper function of any pool sweep cleaner of sand, dust, small debris, DE remnants, etc. An inground swimming pool's main drain is located in the deep end of the pool. So more people and animals can be injured, or worse , electrocuted. After reading that thread, I greatly reduced the flow the main drain to see what would happen (our setup has a valve that can be closed to shut off the MD). Instead, it is an outlet, housing a pipe that runs to the pump, which sucks water through a skimmer, then through a filter, then through a heater (if you have one), and then back to the pool via multiple inlets. Swimming pool main drains are one of two mechanisms used in many pools to circulate and filter their water, the other being skimmers. My pool in NJ has a skimmer and main drain and I find the main drain helps tremendously with small debris and small items that fall to the bottom. For pools with separate main drains, on a dedicated pipe: Never operate the pump with on main drain only, when swimmers are in the pool. My pool has two main drain openings, to prevent entrapment. I would think a second skimmer would give more benefit. Never use the pool without main drain covers safely in place. Are Pool Drains Dangerous? Teach the children of the dangers of main drain entrapment. Another reader commented on the need for sump pumps in draining pools without main drains. Main drain entrapment occurs when the suction is so great through a single main drain that a person can become stuck on or in the drain. February 2009 . Skimmers sit near a swimming pool's waterline, taking in water via gravity and letting it flow down to the filter. Swimming pool main drains are one of two mechanisms used in many pools to circulate and filter their water, the other being skimmers. “I guess the use of an electrical sump pump to drain pools will be the norm. Swimming pool main drains don't move water, pool water inlets do; swimming pool main drains can be used to receive water, but they don't actually move pool water. The drains are positioned at the pool’s deepest point. During winter months or periods of non-use, most pool drains do not need to be plugged, but in some cases plugging a main drain is required or recommended. Are main drains necessary in an in-ground pool? This "expert" is expensive for free! The few gunite pools that do not have a main drain were either built by diletants or main drain was deleted due to a leak on the return piping. Having 2 goldens, it does a great job of collecting the hair in one spot, which I manually pull out. I almost never use mine. A reader asks: I'm attempting to drain my inground plaster swimming pool for the first time, to do some plaster repairs.I have never drained it before. Most pools have two main drains, but a small pool may have only one. When this configuration of the plumbing exists, a vacuum plate is necessary in order to vacuum to pool. Now I do not want to cause alarm with pool owners and swimmers since the vast majority of pool drains pose no risk to bathers, but the reality is that pool main drains can be dangerous.