Swimming Pool Help Center

Why is the pressure in my sand filter so high?

Do I have to backwash my sand filter daily? How do I know when to backwash?

How do I backwash my sand filter?

Why is sand going into my pool?

Sand filter is running in short cycles. Why?

Why won't my filter keep my pool clean?

I have algae in my pool and my filter isn't clearing it up. Why?

I have noticed sand is coming out my backwash line during backwash. Is this normal?

When the dial valve is set on filter, water is leaking out the backwash line. Why?

How often does the sand need to be changed?

How do I change the sand in my filter?

I have very little flow back to the pool, the filter pressure is low and water is coming out of the backwash line. Why?

Air is accumulating in my filter tank and when I turn my pump off, I notice air rushing back into the pump and into the pool through the skimmer. Why?

There are several positions on the filter valve. What does each position do?

Cartridge Filter - When I vacuum my pool, I see debris going back to the pool. Why?

Cartridge Filter - How long will my element last? Should I replace it every year?

What if the support bands break or come off the element of my cartridge filter

What is the best way to clean the element of my cartridge filter?

After I clean the cartridge element and replace the lid and ring-lok, I notice water leaking at the ring-lok. Why?

Should I acid clean my filter element?

My D.E. filter is running at high pressures and has a slow flow of water returning back to the pool. Why?

How often do I need to change the D.E.?

Can I backwash the D.E. from my filter?

What is the proper way of cleaning the grids in my filter?

Why is my filter returning D.E. or debris back to the pool?

After I clean the grids of my D.E. filter and reassemble the filter, I notice water leaking at the ring-lok. Why?

Should I acid clean my D.E. filter grids?

Why is water leaking out of the waste line when the valve on my filter is set to filter?

My filter is noisy. Why?

My pool won't stay clear. Why?

High pressure typically means that the filter sand is dirty and needs backwashing. Follow the instructions for backwashing in your Owner’s Guide or follow the instructions noted on the label located on the tank body. Check to ensure that no valves are closed in the return line to the pool and that there is no blockage in the return line. Over time, the sand in your filter can become calcified or hardened from chemical buildup. If this has occurred, you could add a degreaser to try and loosen the sand. Often if this has occurred, the sand will need to be replaced.


	No. Excessive backwashing is not recommended. Over time, the effectiveness of the sand bed to remove particles improves. Backwash the filter when the pressure increases 10 psi above the pressure when it was clean. Typically, a clean filter will run at 10-15 psi, so backwash when the pressure is 20-25 psi.

Turn the pump off, turn the filter valve handle to “Backwash”, turn the pump on. Typically it will take 2-3 minutes to backwash the debris from your filter. If your filter has a backwash sight glass, backwash until the water is clear. Turn the pump off, turn the filter valve handle to “Rinse”. (Note: This setting is not available on all valves. If you do not have a rinse position on your valve, set the handle to “Filter” and restart the pump). Turn the pump on and rinse for 20-30 seconds. This action removes any debris trapped in the filter during backwash. Turn the pump off. Turn the filter valve handle to “Filter” and restart the pump.


	The most common cause is a cracked lateral in the underdrain system. You must remove the sand from the filter and inspect the lateral/underdrain system and replace any cracked or damaged parts. The sand you are using may be too small, allowing it to pass through the underdrain system. The proper grade sand is #20 silica which is .45-.55 in size. Consult with your local pool dealer.

Improper backwashing could be the reason. Always backwash until the water runs clear in the valve's sight glass; this usually takes about two minutes. You may have live algae causing the filter to clog. By testing the water balance with a test kit and super chlorinating, you should solve this problem. NOTE: Many test kits are very misleading - we suggest that you take a water sample to your pool dealer for evaluation. Be sure to take a sample of water before you shock the pool.

You may not be running the pump long enough. Typically you should run the pump 8-12 hrs. a day or until you turn the entire volume of your pool once a day. Check your chemical balance. Out of balance water can cause cloudiness. Make sure you have the proper amount of sand in your filter. Remove the dial valve and inspect the level of sand - it should be 1"-2" below the bottom of the basket. Also make sure the upper standpipe and lower standpipe are connected tightly into the basket. How old is the sand? The sand should be replaced every 5 years to ensure proper filtration.


	Pool filters cannot filter out live algae. The algae should be killed by super chlorinating your pool water. Once this is done the dead algae can be removed with the assistance of a flocking agent. Consult your local pool dealer on chemical recommendations.


	No, you should not lose sand during backwash. This usually indicates that the backwash flow rate is too high and needs to be reduced. This can be done by putting a valve on the backwash line or installing a restrictive adapter in the backwash port.

A small amount of debris or sand may be trapped between the diverter gasket and the valve plate. To clean the valve, push down on the valve handle while the pump is running. This will flush out the valve and usually resolve the problem. Note that when you push down on the valve handle, water will pour out of the backwash port. If flushing the valve out does not resolve the problem, then you will need to remove the valve cover and visually inspect the diverter gasket for debris or damage. Clean valve body and diverter gasket with water or replace diverter assembly if necessary.


	As preventative maintenance, we recommend replacing the sand every five years.

Set the dial valve handle to the test position. Remove the dial valve at the tank flange (the valve will be attached by hex head bolts or a stainless steel clamp). Remove the upper diverter and basket assembly. The easiest way to remove the sand is by using a wet/dry shop vacuum. (Note: Place a plastic trash bag in the shop vac. canister for easy disposal). If you do not have access to a shop vac., then you will have to scoop the sand out of the tank. If you scoop the sand, be careful not to damage the underdrain system when you reach the bottom of the tank. We do not recommend laying the tank on its side, as this could also damage the underdrain system. Once the sand is removed, fill the tank half way with water. Cover the standpipe opening. (Also cover the tank flange bolt holes, if applicable). Slowly pour the appropriate amount of sand into the tank. Remove the cover over the standpipe. Replace the diverter and basket assembly if applicable. Install the dial valve.


	The hoses are connected to the filter valve incorrectly. The three connections on the valve are labelled: PUMP, RETURN, WASTE. Make sure the hose from the pump is connected to the port marked PUMP and that the hose to the pool is connected to the port marked RETURN.

The underneath side of the dial valve has a small hole drilled in it, which allows air to return to the pool through the return fitting. This hole may be clogged and you may need to remove the valve and unplug this air relief hole by inserting a wire (e.g. straightened paper clip) or anything available that will fit in the hole. This hole is drilled in the ramped section on the underneath side of the valve.

Filter - Water is distributed onto the sand bed. The water flows downward through the sand bed as dirt and debris are captured by the sand. The clean water enters into the distribution system at the bottom of the tank. This clean water is pushed up the center standpipe and returned back to the pool. Backwash - Water is directed into the center standpipe and enters the distribution system at the bottom of the tank. The water flows upward through the sand bed washing the dirt and debris up and out of the filter through the waste line. Rinse - Water is distributed onto the sand bed. The water flows downward through the sand bed to settle it after backwashing. The water enters the distribution system at the bottom of the tank and is pushed up the center standpipe and discharged out the waste line. (Note: This position is not found on all valves and is only used after backwashing). Whirlpool - Water flows directly through the valve and is returned back to the pool. This position is used if you do not want to circulate water into the sand bed. Drain - Water flows directly through the valve and out the waste line. This position can also be used to vacuum heavy amounts of debris to waste. Winterize - This position lifts the diverter up from the valve plate to keep the diverter gasket from flattening out during the off-season. It also allows air to enter the tank when draining.

Water may be bypassing the element through a hole or tear in the element. Inspect the element and replace if necessary. The element may not be positioned properly on the dirt catcher. Make sure the element is positioned so that THIS SIDE UP is showing and that the element is sealed at the top of the dirt catcher. The element may have collapsed causing debris to bypass at the top of the element where it seals to the dirt catcher. Visually you will be able to see if this has occurred because the pleats on the element will not be vertical towards the top of the element. This typically occurs if the pressure has been high (25-35 psi) for extended periods. If the element has collapsed, it will need to be replaced. The dirt catcher could be cracked. Inspect and replace if necessary.


	The element is designed to last a couple of seasons if it is properly maintained. The signs of a worn out element are: support bands are loose or missing, cartridge material is torn or ripped, pleats have deflected and are not vertical at top of element or filter pressure remains high even after thorough cleaning. Routine maintenance is the key to extending the life of an element.

The bands are carefully adhered to the outer edge of the pleat knuckle and will not come loose or break in normal use. However, acid soaking, rough handling or the use of a high pressure car wash sprayer can cause the bands to break and in some instances even separate from the element. Loose or missing bands often indicate a worn out element and indicates that it's time to replace the element. A split band, even if broken in several places will not affect the filtration performance of the element.

Spray the element from the inside/out to force debris out of the pleats, or spray water at an angle to the pleats to wash debris away. We do not recommend that you use a high-pressure car wash sprayer, as this can break the pleat bands or tear the cloth. Once you have cleaned the element by rinsing it off, reinstall it into the filter canister. If the pressure does not decrease to your "clean" reading (10-15 psi) you may have a buildup of suntan lotions or body oils that are still restricting the flow. If this occurs we recommend soaking the element overnight in 1 cup of automatic dishwashing detergent to 5 gallons of water. If algae is present, add one pint of liquid chlorine or one quart of liquid household bleach one hour before removing the cartridge element from the cleaning solution. Remove and thoroughly rinse the element before putting it back into the filter housing.


	You should clean and lubricate (Vaseline is fine) the o-ring before you replace the lid. This assures that you get a good, tight seal. The o-ring could also be pinched or damaged. Inspect the o-ring and replace if necessary.

Acid washing is one of the biggest single factors leading to premature element failure. For years, service technicians and homeowners have acid washed D.E. grids. So it seems natural to do the same thing to cartridge filter elements. There is, however, a difference. Grids are coated by application of D.E. powder. The D.E. absorbs oils and other organics before they reach the grid cloth. Cartridge elements have no such protective coating. The polyester fiber used in the filter media of elements actually attracts and holds oils, body fluids and other organic matter. If acid is applied to the filter element in the presence of these organics, you could permanently plug the element. Acid causes the fiber's surface to become tacky. Since acid does not remove organic matter, the tacky surface acts like glue permanently bonding the organic material to the media. The resulting plugged media cannot be restored to its original condition, causing short cycle runs and high differential pressure.

The D.E. may be loaded with too much debris or algae. You need to backwash or regenerate your filter. If this problem continues and you notice on the filter gauge that the pressure rises from 7 - 10 psi above your beginning pressure, you need to regenerate your filter. Refer to your Owner's Guide for further instructions or consult your pool dealer for service. Your pump output might exceed the design flow rate of the filter. Make sure the pump is the right size for your filter. If there is algae in the pool, super chlorinate, backwash or bump/drain and recharge as needed. Make sure you are backwashing properly on your vertical grid filter. Refer to your Owner's Guide for instructions.


	Whenever you backwash your Vertical Grid filter allowing the dirt and D.E. out the waste line or when you regenerate and drain your Perflex or ReGenX filter.


	You can backwash the D.E. from the filter by opening the waste port on the filter and setting the valve handle to the “Backwash” position. Turn the pump on and backwash for 2-3 minutes or until the water coming out of the waste line is clear.

If your filter has a backwash valve, backwash the D.E. from the filter. If it does not have a backwash valve proceed to the next step. Turn the pump off and remove the ring-lok and lid. Remove the grid cassette and wash the D.E. from the grids using a garden hose spray nozzle. You may want to remove the grids from the assembly to ensure that all of the D.E. is being removed. Typically hosing the grids off is sufficient; however, twice a season we recommend soaking the grids overnight in 1 cup of automatic dishwashing detergent to 5 gallons of water. This will remove suntan lotion and other organic residue that builds up over time and can cause problems if not controlled. Before reinstalling the grids, lightly scrub the grids with a soft brush, rinsing them thoroughly with water. Once you have cleaned the grids and removed all the D.E. from the filter, reinstall the grid cassette in the filter and install the lid and ring-lok, keeping the air relief valve open. Place an appropriate quantity of D.E. in a bucket, then add water. Be sure that this D.E. mixture is thin enough so that it can be poured into the skimmer. Turn the pump on and pour the D.E. mixture into the pool skimmer closest to the pump. Close the air bleed valve when a steady flow of water emerges. This will distribute the mixture of D.E. evenly on the grids. NOTE: If you run the pump for an extended period of time before pouring in the D.E. mixture, there is a chance that the grids will be contaminated by debris from the pool.

Inspect the grids to ensure that they are inserted correctly in the manifold. For Landslide or Avalanche series filters make sure that the straps are properly tightened, so that the grids are secure in the manifold. For Earthworks series filters make sure the rubber retainer ring is in place in the groove in the standpipe - this holds the grid cassette together. Inspect the grids for holes or tearing. Replace if necessary. Inspect the manifold for cracks. Replace if necessary.


	You should clean and lubricate the o-ring before you replace the lid (Vaseline is fine); this assures that you get a good, tight seal. The o-ring may also be pinched or damaged. Inspect the o-ring and replace if necessary. The lid sealing surface should also be cleaned each time the filter lid is removed. This ensures that the o-ring has a clean surface against which to seal.

Here is a simple test to determine if acid washing is required. After thoroughly cleaning the grids in a soapy water solution, rinse the grids with a garden hose to remove all traces of soap. Apply several drops of acid directly to a small area of the filter media. If no bubbling is observed the grids most likely do not require acid washing. If bubbling occurs, this is an indication that a build up of calcium or minerals is present and a mild acid soak is necessary. Soak the grids in a separate solution of one part muriatic acid to twenty parts water; leave grids in the solution until the bubbling stops. Thoroughly rinse the grids before installing them back into your filter. IMPORTANT- Acid wash only when required, if at all, and never without thoroughly cleaning in soapy water or with a degreaser first. WARNING: Wear rubber gloves and safety glasses when using acid or chlorine. Do not mix chlorine or liquid bleach with acid. Always add acid to water. Please Note: If you are using Baquacil or soft swim products contact your local dealer for proper cleaning instructions.

Dirt or D.E. has worked its way under the valve and is creating a path for water to bypass to the waste line. Remove the grid cassette from the filter and loosen the dial valve thumb screw located at the bottom of the filter. Remove the valve spring and handle. Then remove the valve from inside the tank. Inspect the gasket on the underneath side of the valve for debris. Clean the gasket and the tank valve sealing surface and reinstall the valve. If the gasket is damaged, the valve will have to be replaced.


	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 quiets down, this could be an indication that the problem is excessive flow. It can be quieted down by installing smaller eyeball fittings in the return(s), changing the impeller size in the pump, or changing to a 2" control valve.

Your pool chemistry may be out of balance, allowing algae to multiply. The flow rate through the filter may be low due to clogged or undersized piping. Cleaning the lines or changing to larger pipes will correct this problem. Your filter operation time may not be long enough to compensate for heavy use or hot weather. Try running your filter for 24 hours to clear the water, then adjust to less running time. Your pump may be hooked up to the wrong port on the multiport valve; this is rare but it happens. If it is hooked up incorrectly the filter will be flowing in reverse. Be sure the pump is connected to the port marked "pump" on the valve.

Click to Display Catalogue Links
Customer Comments Share \| \|
In-ground Pools On-Ground Pools (New)	Above Ground Pools Wood Above Ground/Onground Pools	The Clearance Page Europe Clearance Page	Wet Deck Aquatic Access	IPG Curve Spas
Pool Pumps & Filters Cartridges Replacements		Pool Cleaners Pool Devil Surface Pool Cleaner	Quartz Patio Heater Leaf Nets, Winter & Safety Covers	Spas and Hot Tubs Spa Accessories
Pool Heaters Pool Heat Pumps	Swimming Pool Lights Fiber Optic Lighting	Slides, Boards and Steps	Turn Your Pool Into a Swim Machine	Goldline Controls
Pool Liners Pool Liner Guard & Wall Insulation	Above Ground Fencing Above Ground Steps	Accessories & Maintenance	Pool Games Sanitizing Systems (UV / Mineral)	Solar Heating Pool Solar Covers
Liquid Solar Blanket		Pool Alarms	Salt Water Chlorine Generator & Controls	Solar Cover Storage System Zeobrite Filter Media