The sun is shining and everyone is anxious to go for a swim. The last thing anyone wants is pool repairs during prime swimming season. Pool filtration is a simple process that we might not give much consideration to until something goes wrong. Cloudy water is one indication that a pool filter may not be performing effectively. What can go wrong? How can filter problems be prevented? Let's consider how to maintain a pool filter.
Whether it's a cartridge filter or a sand filter, they ultimately perform the same task; removing particulate from the pool water. As water is drawn from the pool, it passes through the pump and then through the filter, which cleans the water before it returns to the swimming pool. We might not think there is much grime in our pool, but that's because it's getting trapped in the filter. Everything from dirt, pollen, bugs, hair, cosmetics, sunscreen, and other unmentionables get caught in the filter media. Over time these deposits accumulate and plug up the filter which causes extra pressure in the system. Most filters have a pressure gauge that helps to determine when the filter is dirty. When the pump is off the pressure should read zero. When the pump is running and the filter is clean, the pressure gauge will show the normal operating pressure (this will vary somewhat from one pool to another). When the pressure on the gauge climbs 8-12 pounds above normal, it is time to clean the filter.
In short, a dirty filter can result in a dirty pool. Once the filter is plugged cloudy water can happen over night and could even lead to an algae outbreak. A plugged filter can put extra strain on the pump and could inhibit the circulation of the pool.
Clean filters often! For cartridge filters, the filter canister should be opened (with the pump off) and the filter cartridges can be manually rinsed off with a garden hose and then placed back in the canister. (See your owners manual)
Sand filters will need to backwashed when they are dirty. To backwash the filter, begin by switching the pump off and turning the handle on the filter dial valve to 'backwash'. Turn the pump back on and allow it to run until the water in the sight glass is clear, or for approximately 3-5 minutes. Next, turn the pump off and change the filter dial valve to the 'rinse' setting. Turn the pump back on and allow it to run for 45-60 seconds. After this is done, the pump should again be shut off, and the dial valve handle can be returned to the original 'filter' mode, and then the pump can be turned back on.
In addition, filters need to be chemically cleaned on a regular basis. At least annually, filters need to be de-greased, and stripped of oils, algae and other contaminants that stick to the filter media. Usually this involves letting the filter soak in a chemical solution for several hours. (Follow the direction on the cleaning agent) Doing this will help prolong the life of the filter media and result in clean, clear water.
If these steps are done on a consistent basis cartridges can last between 1-3 years, and sand should last between 5-7 years before needing to be replaced. There are exceptions to every rule, and things such as algae blooms, or heavy bather loads, or other situations out of the ordinary could mean performing some of the above mentioned tasks more often. They key is to keep things clean, be diligent about maintenance, and never hesitate to seek the advice of a pool professional.