Q: What is the difference between a Sand, Cartridge, or D.E. filter A: Sand - Filter Range 20 to 40 microns. The oldest and most popular method of filtration is sand. Sand filters use a special filter sand, normally .45 to .55 mm (also known as pool-grade #20 silica sand), because it has sharp edges that serve to separate particles, allowing filtration to take place. Sand filters are the least expensive of the three types of filters but only filters particles down to 20 to 40 microns in size. Cartridge - Filter Range 10 to 20 microns. Cartridge filtration has been available for a relatively long time, and recently has begun to enjoy rapid growth and acceptance. When water passes through a cartridge filter, dirt is screened out at the surface of the cartridge element. When clean, the element will trap larger particles, with finer particles being filtered out as the pores of the element become clogged by the larger debris. The cartridge element can be removed and cleaned by pressure washing inside and out with a garden hose.
D.E. (Diatomaceous Earth) - Filtration Range 1 to 3 microns. Many pool professionals consider D.E. filtration to be the finest, because it is capable of removing smaller particles than either sand or cartridge. Diatomaceous earth is a porous powder with microscopic openings, that, when magnified, look like tiny sponges. Clear water can pass through these openings but particles, as small as one to three microns are trapped the first pass through the media. All D.E. filters have internal elements that become coated with D.E. It is this "filter cake" that strains dirt, dust, algae and some forms of bacteria from the water. Similar to sand filters, when a D.E. filter becomes dirty, it is cleaned either by backwashing the clogged D.E. to the "waste" line or regenerating and draining. To restore filtration, a fresh "charge" of D.E. is added to the filter.
Q: Should I upgrade to a larger pool filter? A: Pool water filtration is the heart of your water care system. Depending on the size and style of the filter selected, you can achieve energy savings and improved water clarity by reducing the time and energy your pump must exert to cycle the entire body of water in your pool during a 12-hour period. Save energy and time by selecting a larger filter versus a standard filter size. A larger filter provides more filtration area, thus reducing back pressure buildup over time, and strain on your pump. A larger filter can extend the periodic maintenance cycle, thus saving the homeowner valuable time.
Q: Should I do anything to my filter or equipment when I close my pool down for the winter? A: Cleaning your sand or D.E. filters when you close your pool for the season will ensure that they are ready for action when you open your pool the following summer. When closing your pool for the season, coat all accessible o-rings, rubber fittings, and gaskets with a silicone O-ring lube to keep them from drying out.
Q: Is there any way of sealing a leak in a filter tank? A: Unfortunately, there is no way to safely seal a leak in a filter tank. The best option is to replace the tank.
Working with your Cartridge Filter
Q: How do I clean my filters cartridge? A: When cleaning cartridge filters, soak them in a cleaning solution for 24 hours, then hose them off before reinstalling.
Working with your D.E. Filter
Q: How often should I clean my D.E filter? A: D.E. filters should be disassembled and cleaned at least once per season.
Q: How often should I change my D.E.? A: You should change your D.E. after backwashing your filter.
Q: I seem to have to regenerate my D.E. filter frequently. Could too little D.E. be the cause? A: Yes, too little D.E. could cause your pressure to go up. Too little D.E. would not coat the grids and the debris that you filter would get embedded in the grid cloth causing it to become clogged. You probably should take the grid assembly out, clean it off, and soak it in a solution of TSP and water for 12 hours. After soaking, spray off the grid assembly thoroughly. Finally, reassemble it and precoat it with the correct amount of D.E. (refer to you owner's manual). You should see a big difference in the performance of the grid assembly.
Q: I have a D.E. filter. Do I need to add diatomaceous earth to the filter through the skimmer before or after I backwash? A: Diatomaceous earth should be added to the filter after backwashing.
Q: How does the micron filtration rating for a D.E. filter compare with that of a cartridge filter & sand filter? A: A sand filter rates at approximately 20-40 microns while Cartridge filters are rated at approximately 10-20 microns. D.E. filters are rated at approximately 1-3 microns. So you will get better filtration with the D.E. filter. You can make a cartridge filter a little more efficient by adding 1/4 to 1/2 pound of D.E. through the skimmer.
Q: How do I Backwash my Hayward D.E. Filter? Models EC30, EC40, EC50, EC60, EC65, and EC75
Working with your Sand Filter
Q: Why is dirt passing through my sand filter? A: A number of things could be causing the problem. It could mean that a lateral is cracked or broken, or a valve may need servicing. Or, air may be passing through the filter, causing a channeling effect that permits dirt to get by the filter. In the latter case, there may be nothing wrong with the filter.
Q: I have a 10 year old sand filter. How can I determine if the sand needs to be replaced? A: The general recommendation is to backwash your filter when the pressure reaches 10 psi over the initial start up pressure. For example, if the start up pressure is 15psi, you should backwash when the pressure reaches 25psi. If the pressure does not return to the start up pressure after backwashing, it is time to change the sand.
Q: I have a sand filter and I'm getting a lot of sand in the bottom of my pool. Do you think there is something broken inside the filter, or do I have another problem? A: If you are getting a lot of sand in the pool there may be a lateral broken in the bottom of the filter. If this is the case, the lateral(s) will have to be replaced.
Q: How can I find out how many pounds of sand I need to put in my sand filter? A: Refer to your filter owners manual
Q: How do I change the sand in my top mount sand filter? A: To replace the sand in your filter you must first disconnect the pipes going into the valve on top of the filter. Next, unscrew the complete valve counter-clockwise. Once the valve has been removed, you will be able to see the sand bed. The best way to remove the sand is to either use a portable vac or just dip it out with a small can. Once the old sand has been removed, fill the tank 2/3 full of water and just pour the new sand in. DO NOT get sand in the vertical pipe sticking up from the bottom of the filter tank.
Q: How do I Backwash my Sand Filter?
Trouble Shooting your Swimming Pool Filter
My sand pool filter is running at high pressures.
My pool sand filter is running in short cycles.
There is sand at the bottom of the swimming pool.
My cartridge filter will not clear algae from the pool.
My DE filter is running at high pressures and has a slow flow of water returning back to the pool.
My DE filter short cycles even after I backwash or regenerate and recharge.
My DE filter is leaking back into the pool
My DE filter has short cycles when vacuuming
This is normal if the swimming pool contains very dirty water. Backwash or regenerate and recharge more often. If there is a presence of live algae, add enough chlorine sanitizer to control this growth, then vacuum. The presence of alum or floccing agents will clog the filter. Vacuum so as to bypass the swimming pool filter. Do not use floccing agents with DE pool filters.
Will backwashing or regenerating my DE filter thoroughly clean my filter?
No, you must thoroughly clean the elements at least once a year. You can clean your filter elements using automatic dishwasher detergent. Remove the elements from the swimming pool filter, according to the instructions in your Owner's Guide, and hose them off with a forceful stream of water from your garden hose. Fill a large plastic container with the detergent, using about a 1/2 cup and warm water. Soak the elements for approximately 3 - 4 hours. After soaking, rinse off the elements again. Re-assemble your filter according to the instructions in your Owner's Guide. Note:do not soak elements in muriatic if the pool uses Biguanide products. This will damage the swimming pool filter. You may choose to clean the elements with muriatic acid or other commercial pool filter element cleaners, mix according to the package instructions. Use extreme caution when handling any cleaning agents, as they can be harmful to the eyes, skin and clothing. After cleaning, thoroughly rinse all elements with cold water.
The swimming pool won't stay clear .
My swimming pool filter is noisy
An oversized pump may cause noise in your filter valve due to excessive flow. To test, hold your hand partially in front of any returns at the pool wall. If the noise subsides, this will confirm that the problem is excessive flow. It can be remedied by by installing smaller eyeball fittings in the return(s), changing the pump impeller size in the pump, or change to a 2-inch control valve.
My Vari-Flo valve leaks to waste
The valve seat gasket inside the valve has become worn or loose. You may choose to do this yourself or contact your local pool dealer for service. How do you replace the gasket? You will need a new gasket, obtained from your local dealer, some Krazy Glue, and a sharp 1/8-inch wide flat bladed screwdriver. NOTE: Mark the top and bottom of the valve with a marking pen. It's very important that you do not change the location of the cover when re-assembling. Remove the cover, usually six screws. Using the screwdriver, scrape out every last part of the gasket and cement, in order to get back to a clean flat surface. Put a fair amount of crazy glue on the flat side of the gasket. Place the gasket, flat side down, back into place - let dry for one hour minimum.
Q: My filter pressure gauge has dropped below normal for a clean filter? A: If your filter pressure gauge indicates that pressure has dropped below the normal reading for a clean filter, check to see if you have a clogged pump or skimmer basket.
Q: The valve on top of my screw top fiberglass filter keeps popping off when the pressure reaches 15psi. What can I do to correct this? A: A valve blowing off the top of the filter is a serious problem. We highly recommend that you purchase a new filter immediately. We would not recommend running the filter under these conditions.
To purchase a Swimming Pool Filter please follow one of the links below