Troubleshooting Your Swimming Pool Filter

By Author: Steve Merillat
Total Articles: 14
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The Swimming Pool will not stay clear


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 multi-port valve. If incorrectly installed, the filter will be flowing in reverse. Be sure the pump is connected to the port marked "pump" on the valve.

You could be backwashing too often. Backwash only when the pressure rises 7 - 10 psi over the starting pressure, or when the return flow back into the pool becomes low.

There is sand at the bottom of the Swimming Pool


The sand you are using could be too small, which will go through the filter system, then back into the pool.
Remove the sand and replace it with the proper grade of sand - #20 Silica ...
... or 45-55mm pool sand, which can be found at 1800 Pools Web Site.
Your pump may be too big for your filter. During backwashing the pressure can cause the sand to raise high enough to overflow into the standpipe, allowing sand to flow back into the pool.

Refer to your Owner's Manual for the correct amount of sand for your filter (Owner's Manuals are available online under the product page for your filter).
# There could be a loose lateral located at the bottom of your filter.
? Tighten any loose laterals, replace if broken.
# Most calcium based chlorine, both powder or tablets, contain from 30 - 35% of what is called inert materials. This is calcium residue or dust, which many pool owners mistake for sand.
You can confirm this by following these steps:
? During vacuuming, use a hand vac and pole. As the vac head approaches, the sand will lie on the bottom, and will allow itself to be picked up. Most calcium residue will scatter away from the vac head as you try to pick it up.
# If you have this problem, we recommend that you put extra water in your pool and vacuum to the waste line. If you vacuum to the filter, some of it will be trapped on the sand surface, allowing dust to get back into your pool.

Will backwashing thoroughly clean a Swimming Pool DE 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 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 filter.

You may choose to clean the elements with muriatic acid or other commercial 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.

Your Swimming Pool Cartridge Filter will not clear algae from the pool


The three filter types will clear up algae, provided it is not in a live state. Consult 1800 Pools for the proper chemicals to help rid the algae. Most cartridge filter problems are caused by dirty, clogged or abused elements. Either clean the elements, or replace if torn or damaged.

Your Swimming Pool DE filter has short cycles when vacuuming


This is normal if the 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 flocking agents will clog the filter. Vacuum so as to bypass the filter. Do not use flocking agents with DE filters.

Your Swimming Pool DE filter is leaking back into the pool


Be sure that the suspected material on the pool floor is actually DE. Pollen, chemical residue and plaster dust often look like DE. You may have a tear in your filter elements, replace if necessary. Make sure that you assemble the internal parts properly! Check for air leaks, as this will cause the system to leak DE back into the pool. If there are air leaks, install a check valve between the pump and the filter valve.

Your Swimming Pool DE filter is running at high pressure


The DE filter is loaded with too much debris or algae and needs backwashing or regeneration. If this problem persists and you notice the filter gauge pressure rising 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 correctly sized for your filter.

If there is algae in the pool, super chlorinate, backwash or bump/drain and recharge as needed. Make sure you are properly backwashing on your vertical grid filter.
Refer to your Owner's Manuals for instructions.

Your Swimming Pool DE filter short cycles even after I backwash


The filter elements may be clogged because of an accumulation of chemical deposits. Clogging is accelerated if chemicals are fed through the skimmer, operating your filter too long without DE after starting the pump, or operating the filter without DE. DE must be added as soon as the filter is full of water, and the pump is putting out a steady stream of water. Refer to your Owner's Guide for the amount of DE your filter requires. Biguanide based sanitizers (i.e. Baquacil, SoftSwim) can cause short cycling.

Your 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 installing smaller eyeball fittings in the return(s), changing the pump impeller size in the pump, or change to a 2-inch control valve

Your Swimming Pool Flow 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.

Your Swimming Pool Sand Filter is running at high pressures


Follow the backwashing instructions in your Owner's Manual. The sand bed may be clogged with mineral deposits that will not backwash away. Some calcium based chlorines and other alternative sanitizers will build up in your sand bed, and will require more frequent backwashing and changing of the sand.
Before you replace all the sand in your filter, try removing approximately 1" of the top layer of the sand, replace with the exact amount of sand you removed.
Normal life span of the sand is about 4 - 5 years.

You may have to clean your filter system with a special filter cleaner, check with your pool dealer for proper procedures.

Check to see if there is a closed or partially closed valve along your return piping, open the valve.
Your pump may be too small to provide sufficient flow for proper backwashing. Your filter will function, but a lower design flow rate will cause your system to backwash improperly. Check the output of the pump to be sure that it equals your filter's design flow rate. Replace the pump if it is too small
S.Merillat(r)

To learn more about Troubleshooting your filter, visit http://www.1800pools.com
Steve Merillat has been in the Pool industry for 35 years. He started early on working for various Swimming Pool supply companies before ventured out in his own business. He pioneered many processes with the installation of pools that are used as industry standards today. He regularly holds seminars and classes on how to properly maintain your Swimming Pool. Visit http://www.1800pools.com