The first thing is, you must know what your normal operating pressure is. Your normal operating pressure is the PSI reading right after you backwash your filter in the beginning of the season. It generally runs between 5 and 15 pounds, depending upon how far your filter is from the pool.

Backwashing your pool filter should be done after your filter reaches 10 pounds above normal running pressure. So if your normal running pressure is 10 pounds, when it reaches 20 pounds it is time to backwash. First clean out the baskets in your skimmer, and your pump. Turn off your filter and adjust your multi-port or push/pull valve to the backwash position. (Never adjust your multi-port or push/pull valve, while the filter is running). Then turn your filter back on and run it until the water starts to clear up in the sight glass. Once the site glass is clear, turn your filter off and turn the multi-port or push/pull valve back to the filtering position. Turn your filter back on & count to three, and then turn it back off. Adjust your valve back to the backwashing position and then run your filter until the water clears in the sight glass once again. Repeat this step three times, as this will thoroughly clean out your Sand or Diatomaceous earth filter. If you have a multi-port valves, before you adjust back to the filter position for the last time, adjust your valve to the waste position and run the filter until the water clears in your sight glass. This will clear out any remaining dirt left in your plumbing or your valve. Turn your filter off, adjust your valve back to the filter position, and turn your filter back on.

If you have a DE filter, after backwashing the filter, you will need to recharge it with diatomaceous earth. It is advised to put the proper amount of diatomaceous earth in a bucket first, then turn your filter on, go to the closest skimmer to the filter, and pour it into that skimmer. Only pour as much as the skimmer can take each, time until your bucket is empty. After you have poured the recommended amount of diatomaceous earth in the skimmer, wait for 2 minutes, and then turn the filter off, wait 30 seconds, and then turn the filter back on for normal filtering.

Here is a tip for recharging your filter, When you install your clean grids back into your filter for a new season of filtering, you will want to use one less pound of diatomaceous earth after your first backwashing. So if you start out the season with 5 pounds recommended by the manufacturer, the next time you recharge the filter you will add 4 pounds. No matter how good you backwash your filter, you will always leave at least 1 pound of diatomaceous earth attached to the grids.

By following this procedure, you will prevent the grids from becoming too clogged before the end of the season, which would result in you having to removing the grids and thoroughly clean them during the season.

(Recommendations for the proper amount of diatomaceous earth to recharge your filter)

24 square-foot use 4 pounds to start and then 3 pounds to recharge

36 square-foot use 5 pounds to start and then 4 pounds there after

48 square-foot use 6 pounds to start and then 5 pounds

60 square-foot use 8 pounds to start and then 7 pounds

72 square-foot use 9 pounds to start and then 8 pounds

For diatomaceous earth filters, after about two or three years you may notice your normal running pressure increase each time you backwash your filter. If your normal running pressure was 5 pounds, and in a few years, it has increased to 10 pounds, this means calcium has built up on your grids and they will need to be removed from your filter and cleaned out in muriatic acid. This should be done professionally. Most local pool stores will offer this service.

For cartridge filters, the filter cleaning is a bit different. For your standard filter that has a single cartridge in it, you will need to clean your cartridge, when the filter reaches 10 pounds above the normal running pressure. This may need to be done every one to two weeks for pools and spas. If you have a gang cartridge filter, meaning there's more than one cartridge, once it reaches that magical 10 pounds above the normal running pressure you will have to clean it also. The difference between a single cartridge and gang cartridges is that the filters with multiple cartridges generally don't need to be cleaned more than once or twice in an entire pool season. To clean a cartridge filter you remove it from the housing and spray with a garden hose or one of the cartridge spray cleaners that we sell. Do not use a power washer, as it will cause the filaments to fray, thus damaging the cartridge. At that point it will need to be replaced. After spraying down the cartridge, it wouldn't hurt to soak your cartridge in sodium bi-phosphate for about five hours, and then rinse it off. This will remove any oils that have accumulated to cartridge. Then you can install it back in your filter housing.

Some things to look for during your pool season concerning your filter:

For sand filters, if you notice small amount of sand after you vacuumed the pool, chances are the laterals in your filter have dried out and cracked. In order to repair, you will need to remove the sand from the filter and unscrew the laterals from the bottom of the tank. Let us know what kind of filter you have, or send us a picture so can assist you. We can send you a whole new set of laterals then. They are relatively inexpensive and easy to replace. Just screw them back in the lateral hub, and refill with fresh filter sand.

For diatomaceous earth filters, if you notice, a white powder, appearing on your pool floor after each vacuuming, the chances are one or all of your grids have cracked and have holes in them. Remove them from the filter, and let us know what kind of filter you have. We then can send you the grids that you need. This is also relatively easy repair. Just replace the damaged grids, and reinstall him back into the filter and recharge.

For cartridge filters, if you notice dirt reappearing on your pool floor shortly after you vacuum, the chances are one or all of your cartridges will need to be replaced. Cartridges can be easily removed from your filter. Just give us the number off your cartridge, and we can send you a replacement. Just reinstalled back in your filter housing and you'll be good to go.