Unblock-able drain covers for swimming pools?

Answer 1

Every main drain should have a drain cover as a swimmer may become trapped by hair length or suction if the skimmer is turned off and the filtration intake is coming from the drain only. There are grated covers for rectangle drains and there is little that can be done there but in round drain housings there are anti-vortex drain covers which is recommended. New codes from the National Pool and Spa Institute (NPSI) says that two drains should be installed on new installations a certain distance apart so if one is covered by a swimmer that the second is still open to avoid entrapment. GREAT care should be taken to ensure that swimmers with longer hair such as girls, should not swim near operating drains. On residential pools ALL swimming filters should be turned off with swimmers in the pool. The pool loses its circular motion that ensures debris meets the skimmer(s) or drains anyway. Care should also be taken that long haired swimmers not swim in front of skimmers in operation also. Hope this answers your question.