Chlorine tablets are the most common and efficient sanitizer to use in above ground pools. These tablets are compressed so that they dissolve slowly and steadily release free chlorine into your water to wipe out bacteria and keep your water clean. Chlorine also comes in sticks and granules. Whichever form you decide to use, you’ll want to look for stabilized chlorine which is processed to protect it from the sun's damaging rays, making the chemical last longer and work more effectively. Always keep chlorine in your skimmer, floater, or automatic feeder for continuous sanitizing.
As debris builds up in the water - from perspiration, suntan oil, hair spray, etc. - it can cause eye and skin irritation and dull water. Often, chlorine is blamed for irritation and odor when in fact the real culprit is contaminants which tie up chlorine, keeping it from effectively sanitizing the water. When this happens, you should use shock which is basically a concentrated chemical treatment (usually chlorine). Shocking your above ground pool once a week will oxidize contaminants, freeing up the chlorine, and keeping your water crystal clear. Regular shock treatments will also kill resistant algae in the water. There are a variety of different products available including non-chlorine shock and shock designed for hard water areas.
Since algae is visible, it tends to be the pool problem that is most disturbing to pool owners. This is not surprising as no one wants to see black, green or yellow fuzz growing in their pool. In reality, it is not the algae that are harmful but the waste they produce by converting sunlight into food. This waste then feeds bacteria which is the real problem. Algae spores travel through the air and enter pool water. With just a few hours of sunlight on a warm day, algae can colonize your pool if your chlorine level is too low. The best way to combat algae is to never let them get started. Regularly checking to make sure your chemical levels are adequate and your pool water is balanced is vital. Adding algaecide is another preventative measure which will help prevent all types of algae from getting a foothold in your pool. You can use algaecide weekly to discourage algae growth.
If algae have already taken hold in your pool, there are some basic steps to follow. First, shock your pool and keep your water circulating 24 hours a day if possible. You are looking to achieve 10 ppm of chlorine. After shocking, you will need to brush and vacuum the entire pool. Follow up with an algaecide designed for your particular algae problem (most common are black, green and mustard algae). Brush and vacuum again and try to repeat this each day. Check chlorine and add more if it’s below 5 ppm. It is also recommended that you regularly clean your filter during this process.