The pool should not need draining, and to do so can be the worst thing you ever do as it can causes changes in the pool wall forces and can lead to micro cracks and leaks.
The pool should have skimmers (baskets filters at the edge at one end or in the overflow around the edge) and a sand filter in the pump room. Water cost is about 80 cents per cubic meter plus chemicals, so this will make it costly as well.
Contamination is usually rain acid or otherwise, rain with fine air borne sand, leaves, insects or soil as per the storm.
The pool gets contaminated all the time, dirt sun oil etc. With the storm the effect is overnight but should not be drained, the only reason to drain is to fix leaks or recover broken glass.
The big bits insects, leaves, humus will be caught in the skimmers or if it flows though it will be caught in the sand filter. The sand filter has a pressure gauge to show when the sand needs changing (special fine sand is in the filter)
The big bits that sink to the pool floor can be hovered up with the pipe with a hoover like attachment the bits and water sucked up either go to a drain or through the sand filter.
The very fine stuff (looks cloudy) that stays in suspension (sand, algae etc.) is treated by adding a coagulant to pool water as a block or gel. The causes the small bits to stick together and then they are big enough they get caught in the sand filter.
At my other community after storms or high temperatures the gardener will add the coagulant, check ph and chlorine and adjust and the pool clears with 24 – 48 hours.
It is safe to swim in even when cloudy provided the chlorine level is I think 1 to 2 parts per million. And the ph is 7.5 about the same as the human eye fluid. At this level of the pool chloride is maintained, other chemicals provide stability of these levels as well.
In Spain we don't winterise pools normally see below.
http://outdoor-living.hardwarestore.com/learning/essential-pool-maintenance.aspx
This message was last edited by manilvajl on 9/22/2007.This message was last edited by manilvajl on 9/22/2007.