October 2012
5-25
five minutes). Backwashing is complete once the water that passes through the
sight glass is clear and free of particulates.
Mineral Buildup Control
Pools and spas must be drained of some water on a regular basis in order to con-
trol the mineral salt concentrations that gradually build up. The frequency of these
events can be reduced by prolonging the useful life of the water by considering the
following:
••
Maintain proper pH, alkalinity, and hardness levels to avoid the need to drain the
pool or to avoid using excess make-up water to correct water quality issues.
••
When draining the pool, perform a partial drain rather than a full drain. Consider
using the drained pool water for irrigation or other purposes. See
Section 8: On-
site Alternative Water Sources
for more information.
66
Leaks
To check your pool for leaks and prevent them for occurring, actively monitor the
pool’s water levels. If the pool is losing more than two inches of water per week, it
could be leaking.
67
In addition, actively monitor for leaks around the pump seals, pipe
joints, piping in filtration system suction or return lines, pool liners, and along the
pool edges. Repair leaks as soon as they are identified.
Retrofit and Replacement Options
If retrofitting an existing pool or spa, there are a several options to minimize overall
water use by addressing evaporation, filter cleaning, mineral buildup control, leaks,
and splashing. If designing a new or replacement pool or spa, use the management
techniques listed in the previous section and the equipment options below.
Evaporation
To prevent water loss from evaporation, cover the pool when it is not in use. In addi-
tion, consider the following to control the evaporation of pool or spa water:
••
Reduce wind movement across the water by using fences, walls, non-shedding
hedges, or other similar barriers.
••
Use a liquid barrier. These alcohol-based chemicals prevent evaporation by
forming a thin film along pool surfaces that acts as a barrier.
68
Liquid evaporation
barrier products are available through pool supply vendors.
69
5.4
Commercial Pool and Spa Equipment
66
Ibid
.
Page 15.
67
Ibid
.
Page 12.
68
Ibid
.
Page 34.
69
Williams, Kent,
op. cit.
