Q. I have an in-the-ground swimming pool which I do not use. Will I ruin it if I drain out the water and leave the pool empty? :Pete Morose :Phoenix, Ariz.
A. A swimming-ppol contractor here in southeast Arizona says his guarantee is void if the pool is left empty for 10 days.
Swimming pools are usually finished with a high grade of white plaster which cures and remains sound when under water. But remove the water, expose the plaster to dry air, and it may cost you a bundle later on to replaster the pool.
The mechanical equipment which filters the water also will deteriorate if unused.
Even the structural integrity of the sides and bottom may be jeopardized by the unequal pressure after the water is removed. This could be a serious matter if there is ground water near the surface. I once knew of an empty swimming pool which literally floated out of the ground when the ground-water table rose from heavy rains.
My recommendation is to keep the pool filled with water, maintained, and the equipment operating.
Cover the pool with a structural wooden deck with a watertight surface, if you wish. This will minimize the upkeep costs and afford needed safety. The next owner may bless you for keeping that old swimming hole alive; and you should find it a good investment by keeping the pool filled with water.