As a pool owner, you probably have a rough idea of how to keep your pool water clean. But are you sure you are doing it right? A swimming pool is a sophisticated piece of equipment. Don’t expect to know everything about it without asking questions or you'll find yourself with smelly water, a green pool and hair to match! When you think about it, keeping fifty tons or more of exposed-to-the-elements water in crystal clear condition is no easy task. An outdoor pool is constantly under assault from algae and fungi spores, garden debris, rain, sun, wildlife, pets, building/quarry/road dust and a host of other pollutants. That's before any humans get in! When pools go bad, they can go bad really quickly.

A properly maintained pool is both visually and biologically clean. You can tell if it’s visually clean just by looking at it, but ‘biologically clean?’ How will you know? Use a test kit to measure chlorine and pH levels. (Your pool-shop will cheerfully show you how it’s done; well, one poolshop we know of will…...) Keep the chlorine and pH levels right and your pool will be ‘biologically clean’ - and you will never be troubled by algae. ‘pH’ refers to the acidity/alkalinity level of your pool water. pH level is vital because, unless your pool is within a certain pH range, the chlorine cannot interact chemically with the bacteria and algae it’s supposed to kill. In other words, unless your pH range is properly adjusted, chlorine won’t help keep your pool as clean as it should be. Most pool owners don’t the importance of pH level. The correct range is 7.2 - 7.6.

Measure your pool’s current pH level. If the level is too high (your test kit tells you how to determine that), add ‘pH minus.’ If the level is too low, add ‘pH plus.’ ‘pH minus’ & ‘pH plus’ are stocked by your pool-shop. Now check the chlorine level. The ideal level of chlorine is 1 - 3 parts per million (ppm).

There are different types of chlorine available but we recommend just one type: any chlorine that is described as ‘Stabilised Trichlor’, because it’s very effective in fighting bacteria and algae, it’s very easy to use, and it lasts 4 to 5 times longer than liquid bleach, shock chlorine or calcium hypochlorite. Stabilised Trichlor may cost more initially, but will save you money in the long run. The sun will destroy liquid bleach (‘shock’) and calcium hypochlorite after 4 hours. Stabilised Trichlor will keep working for over 24 hours when dissolved, so more chlorine is left in the water to do the job of sanitising, and less is wasted by being burned off by the sun. Stabilised Chlorine will last longer than 2-3 times the amount of unstabilised chlorine.

For most applications, we usually recommend using the 200 grams slow dissolving ‘hockey puck’ style tablets. With pH at 7.4, one of these tablets (per 50 cubic metres of water) will raise the Free Chlorine by 1.5 ppm. Mix granulated or powder chlorine with water in a bucket first. This ensures that you don't stain your pool. Remember; add chemicals to water, never water to chemicals. Wash your hands after handling chemicals.

Tablets are easier to use; put them either into your skimmer basket or, if you have one, your chlorine feeder. One tablet for each 50 cubic metres is typical, but you may need more in the really hot weather, or after a rainstorm. In addition to pH balance and chlorine level there are several other important aspects of routine maintenance. These include vacuuming, back-washing, super-chlorination (vital for a trouble-free pool), pump-room operations and knowledge of your own filtration/circulation system. We cover all of these subjects and more on our Pool School course, which is customised to each individual pool and pool-system. Pool School Graduates learn all about looking after their own pools - and they get a Pool School Book! (RRP€15)

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Deep Blue Pools, Alhaurin el Grande, 952 594 393
Copyright Ken Walker, Deep Blue Pools, July 2006