Proper pool care is essential to not only maintaining an inviting place to swim, but is also crucial to abiding by the law in several municipalities. For example Phoenix, Arizona has a huge number of swimming pools, and sadly, every summer, children drown in some of them. Often, these drownings happen in pools that have been neglected, and no longer have clear water. A backyard pool with dark, murky green water can hide a child easily, and make rescuing a drowning victim take much longer. In fact, Phoenix law dictates that pool owners keep their pools clean for this reason. Often police will cite people for murky pools that officers noticed by helicopter.
There are several factors that go into keeping pool clear and inviting. The first is understanding a bit of the science behind what makes a pool green and murky in the first place. Lakes and streams often have dark water, especially if the water is stagnant. What makes water dark in lakes is usually the growth of algae. In order to grow, algae needs sunlight, carbon dioxide and the proper pH balance in the water. The key to stopping the growth of algae is a matter of stopping at least one of the factors that are necessary for its growth.
In winter, keeping a pool clear and green is easier than summer, since there is less heat and sunlight, and the algae simply doesn’t grow as quickly. In summer, it’s necessary to add chlorine, and sometimes muriatic acid to the pool to keep the water inhospitable. Chlorine is usually applied via a floater that contains several tablets. These dissolve much more quickly in hot weather than cold. Periodically, extra chlorine will need to be added in the form of powered “shock”. This shock will kill any algae that survives the daily doses of chlorine, but people should avoid swimming for a few hours afterward.
The best way to determine whether the pool needs additional chemicals, such as acid is with a pH test kit. These test a small sample of water which turns different colors depending on whether the pool is acidic or alkaline.