WATER SAVING HINTS
It has been estimated that approx. 12,000 mega litres of water are lost from Queensland's 300,000 residential swimming pools each year as a result of evaporation and backwashing of filters.

Evaporative losses :-
Major causes of evaporation are wind, water temperature, ambient temperature, humidity etc.
The resultant water losses can be reduced by;
A:  Covering the pool when not in use. Pool covers can reduce evaporative losses by up to 90%. They are available in many forms from the inexpensive floating type to a fully automatic, push button, safety cover. Enter swimming pool covers in your search engine.

B:  Fully or partially enclosing the pool. Enclosures are available as solid structures with glass or other panels or simply as an inflated enclosure. Enter swimming pool enclosures in your search engine.

C:  Wind breaks can be achieved by solid fencing, planted hedges.

D:  In design of new or renovated pools, lower the freeboard. ie; increase the distance from the top of the copeing to the middle of the skimmer from the normal 70 – 150mm to 170 – 190mm, and if there is an overflow pipe, use an expanding rubber bung to contain excess rain water. Never let the water level immerse the bottom of the copeing pavers.

Back-washing losses :-
Sand filters on average use the most water for back-washing. Larger filters, on the same volume of contaminated water, require less backwashing. But larger filters require larger pumps (flow rates) to cause agitation of the sand bed, for efficient backwashing. It is imperative, for water conservation, that the filter size is matched to the most efficient flow rate for that sized filter… do not select a pump on horse power alone . All pumps should be selected on flow rate at a specific pressure. The maximum flow rate through a sand filter bed is approx. 800lpm/sq.m. The pump should be selected to pass the entire pool volume through the filter every 4 hours. The filter size should then be matched to this pump as near as possible to 800lpm/sq.m flow rate. A pressure of 9 metres (90kpa) can be assumed as average pressure for most residential pools.

Recommendations for “water conscious” sand filters:-
Pool Volume   Min. filter size    Flow rate @ 9m
40,000 litres      600mm diameter            240lpm
50,000 litres      700mm diameter            320lpm
60,000 litres      750mm diameter            370lpm
80,000 litres      800mm diameter            420lpm