The months of May to August are prime months for enjoying a backyard dip in Arizona. Pools that have sat all year suddenly come to life and don't settle down again until September. This also means that May is the time to make sure that your pool service gets your water prepared for the season. (If you don't use a pool service company, you'll have to do these things yourself.)

Every year swimmers around the country become infected by organisms that are deposited in pool water. Many of these cases occur in public pools. Most of the statistics of water-borne illnesses from swimming are based on public pools.

However, it is estimated that dozens and possibly hundreds more Arizona residents become infected from backyard swimming water. These cases are not always reported to authorities and aren't included in the official statistics.

Children are the most common victims of swimming water illness. However, these kinds of problems can affect swimmers of all ages.

Your water should have been tested (either by you or your pool service technician) at least once weekly throughout the off-season. As long as all those readings were normal, or you adjusted your chemicals as needed, your water is ready for preparation. Now, these pool service info tips will help to ensure your swimming water is safe this season:

1) Test your water at least three times each week during swimming season. Weekly tests are no longer sufficient. Every time people swim, your water's chemistry can change. Even if no one has used the pool for a day or two, it's still important to test often. If your test indicates that your levels are off, add chemicals as needed to restore a proper balance.

You may have a contract with a pool service provider. If so, your technician will check during each visit. It's still important for you to perform checks yourself, though, in between those visits.

2) Don't let swimmers back in if your water tests poorly. It can be hard to say no, especially on a sweltering mid-summer day. However, it's critical that you give your water time to stabilize after a too-low or high reading. Otherwise, you may be inviting parasites and, therefore, the possibility of spreading disease.

The rule of thumb is to close your pool for 24 hours. Then, re-test the water. If your levels are still off, add chemicals and wait again.

Here's a hint: pool service professionals recommend adding your chemicals in the evening. During hot days they, just like water, are prone to evaporation. You'll get more out of them if you wait until the heat dies down.

You can usually correct the problem yourself within 24-48 hours. However, if the problem persists beyond 48 hours then you should call in a professional pool service for a diagnosis.

3) Teach young children not to swallow swimming water. Children, especially babies and toddlers, are prone to this. Unfortunately, they are the ones who tend to be most severely affected by water-borne illnesses. Babies and toddlers have died from swallowing organisms in swimming water.

You might find it helpful to take a parent-tot swimming class with your youngster. If you can' find such a class, arrange for a private lesson. A trained life guard will teach you the proper way to introduce your child to the water. You'll learn how to get your baby used to going under water without swallowing any.

Make sure that older children are aware of the dangers of swallowing swimming water. Usually it takes only a few strong reminders for this lesson to take hold.

4) Check your drain covers regularly. Replace broken ones immediately. Swimming pool drains have enough suction to pull in small arms and legs, even long hair. Children and even grown adults have been known to get caught up in the suction of a drain and drown. If you have a pool service, ask your technician to check your drains.

Your pool service technician is a good source of safety information if you need it. You should also consult with your owner's manual. Every model is slightly different and may have its own quirks. The better you know your own, the better prepared you'll be to keep swimmers safe.