800-574-7665

Live Chat

Free and Fast Shipping

to: Location Unknown Change
  • *Free Next Day Delivery applies to qualified products only and varies by region.

Get Details





How to Select a Pool Filter

Are you looking for the right pool filter to get the job done? Well, you’re in luck. At Doheny’s Pool Supplies Fast we have 3 pool filters that will help you open, maintain, and clean your pool. After all, to keep your water crystal clear it is essential to not only keep the pool itself clean, but your filter that does the ‘dirty work’ as well. Read on to find out which pool filter is the right one for you!

Cartridge Pool Filter- The cartridge pool filter is gaining popularity when it comes to spas and small above ground pools. This particular cartridge is both easy to maintain and clean throughout pool season. It is recommended that you check the cartridge frequently to be sure there isn’t any dirt or debris left behind. All you need to do is remove the filter and spray it with a garden hose to remove excess dirt. The pressure gauge on the filter should be between 8-10 lbs. above the clean reading. However, over time the cartridge will eventually lose its filtering ability, which means that a replacement must be installed to keep the filter running smoothly. Typically, cartridges need to be replaced every 3-5 years, depending on how often you filter your pool.

a. No ‘Backwashing’- With this type of filter you do not need to backwash it to maintain it over time. Actually, there is no backwash valve that will allow you to complete this task in the first place. Although this filter requires more manual labor than most, it might prove worth it in the long run. Backwashing a different type of filter wastes water, so this is the most energy efficient choice overall.

b. Clarifiers- You utilize clarifiers and sanitizers in your pool water, so why not your cartridge filters? Consider one of our clarifiers for a sparkling clean filter in no time.

c. No Debris for You- In order to make your cartridge filter last with as few replacements over time as possible, you need to continuously check your pool water for additional debris, dirt, and organic remnants that could clog the filter chamber. Circulate and balance the chemicals in the water frequently to be sure bacteria and algae don’t populate and overtake your pool water, thus clogging the filter and making the overall experience a tedious and expensive one for pool owners such as yourself. At Doheny’s we want this process to run smoothly for you!

d. Run Your Filter- There are different recommendations as to how frequently and how long you need to run your cartridge filter. It depends on the age of your equipment and how often you filter the pool water. Let’s say your pool equipment is older (we’re here so you can purchase new) you might want to run the filter at the very least an entire day. If your pool equipment isn’t old, then approximately 16 hrs. or so should suffice.

DE (Diatomaceous Earth) Pool Filter- The DE pool filter is by far the most efficient filter in its category. Next to nothing will get past the filter chamber, even particles (up to 2 microns) the naked eye fails to see can’t surpass it. Unlike the cartridge filter mentioned above, this filter uses a pressure gauge to alert you when it is time to backwash the filter. Typically, if it reads 8-10 lbs. higher than the clean reading, backwashing is necessary to keep the chamber clean. In order to clean the filter grids, we recommend Celatom Diatomite Filter Media. Without the DE media, this particular filter simply cannot complete the task at hand. It requires this specific powder to keep your water and equipment clean and sanitary at all times.

a. Backwashing- When your pressure gauge reads 8-10 lbs. above the clean reading, it is time to backwash your filter. All you need to do is turn a valve to allow your pool water to filter backwards to rid it of dirt, debris, and bacteria. Depending on the style of your DE filter; you might have a push valve (aka slide valve) or a multiport valve to complete this task.

b. Backwash with a Multiport Valve-

1. Turn off your pump motor

2. Rotate the valve from ‘Filter’ to ‘Backwash’

3. Get rid of any hoses in your way

4. Open the air bleeder on the filter and turn pump on

5. Keep an eye on the pressure gauge in case the hose starts to kink. It is crucial to keep an eye on the reading at all times. If it is too high, then you need to switch off the pump quickly.

6. Once the hose is full of water, run it for 2-3 minutes or until the water becomes clear.

7. Turn the pump off and move the valve to ‘Rinse.’ Rinse for approximately 5-10 seconds. Once this is complete, switch the valve to ‘backwash’ and turn the pump on again. Check to see if the water is running through the chamber clear, if not, you will need to repeat this process until it does.

8. When the water appears clear, you need to turn off the pump and move the valve to the ‘Filter’ position.

9. Turn the pump on and make sure the pressure gauge is a lower reading.

10. It is recommended to add 1 lb. of DE media once this process is complete

c. Backwash with a Slide Valve-

1. Turn pump off

2. Unlock the T-handle and pull it upwards about 2-3’’

3. Open the air bleeder on the filter and turn pump on

4. Keep a close eye on the pressure gauge for kinks in the hose and/or backpressure build up.

5. Once the hose is full of water, run it for approximate 1-2 minutes until the water is clear

6. Shut off and push the handle down. Turn pump on and filter for about 15 seconds, then turn pump off again. You will need to repeat this process a few times until the water is clear.

7. After the water clears up, turn the pump off and push the handle back into a locked position

8. When you turn the pump back on, check for a lower pressure gauge reading.

9. Add the DE media as recommended above for a multiport valve.

d. Replacing the Grid- These replacements are a slightly more expensive option, but the labor involved isn’t as stressful as you would think. Feel free to purchase a full set of replacement grids so you are prepared when it becomes too full of debris.

e. No Debris for You- In order to make your cartridge filter last with as few replacements over time as possible, you need to continuously check your pool water for additional debris, dirt, and organic remnants that could clog the filter chamber. Circulate and balance the chemicals in the water frequently to be sure bacteria and algae don’t populate and overtake your pool water, thus clogging the filter and making the overall experience a tedious and expensive one for pool owners such as yourself.

f. Run Your Filter- There are different recommendations as to how frequently and how long you need to run your cartridge filter. It depends on the age of your equipment and how often you filter the pool water. Let’s say your pool equipment is older (we’re here so you can purchase new) you might want to run the filter at the very least an entire day. If your pool equipment isn’t old, then approximately 16 hrs. or so should suffice.

Sand Filters If you are looking for a low maintenance pool filter, this might be the right choice for you. Sand filters tend to trap particles within the 20-100 micron range. As we’ve observed with the DE filter the sand filter also requires ‘backwashing.’ If you notice the pressure gauge is between 8-10 lbs. above the clean reading, then you need to backwash and remove all debris from the filter itself. We have good news for you! Sand filters only need to be replaced every 5 years if they are well maintained. The actual sand itself can be replaced every 7 years, but it is always a good idea to observe the filter quality just in case it needs to be changed earlier. Feel free to check out Zeofiber and/or Zeosand to keep your filter clean and clear of dirt.

Repeat steps A, B, and C above (Same process for the Cartridge and DE filters)

j. Filter Run- You should be able to run your filter continuously for approximately 4 weeks. If for some reason you are unable to do so, this might indicate an issue with the filter itself. Dirt, debris, and other organic matter might be clogging the chamber. In that case, you might need to replace the sand bed entirely.

k. Replace Sand Bed- Before you can add new sand media to your filter, you first need to remove the old sand. You need to take apart the filter drain, turn on your pump, and let it run its course. Obviously, you cannot apply just any sand to this filter, you need to use specific pool filter sand (#20 silica sand 45-55mm), after you pour the new sand in you need to be sure that it is centered properly so no excess sand escapes into the pool water.

Now that we’ve given you the basics on how to decide, maintain, and replace various parts within the 3 filter categories above, you can make your final decision. If you have any other questions please do not hesitate to call or email us. Our experienced customer service staff is here to help you with all of your pool filter needs.