Sand filters tend to have a lesser price and they can be fairly easy to maintain. They are commonly sold as a package filter system for above ground pools, as they do not require annual cleaning. Sand filters require backwashing when the pressure in the unit exceeds 8 pounds over the normal levels recommended, usually about 2-3 times per month. Water chemistry also plays a part in understanding your sand filter. Improper chemical balance can lead to the channel of the filter clogging and being blocked with hard sand.
The sand needs to be changed every 2-5 years. Sand filters can go for longer periods of time prior to changing the sand. When the filter sand is new, the sand is coarse and about .45 to .55 mm in diameter. The roughness of the sand is important to the efficiency of the filter as it separates the particles of dirt in your water. Over time, the coarseness of the sand becomes smooth and allows more particles to slip through the filter back into your pool. The worn sand will allow dirt to get into harder to reach areas of the pump where backwashing won’t even get it completely clean.
Changing out the sand in a sand filter can be challenging. Refer to the manual for your filter to change the sand or contact a pool service professional to help. Here are the basics to changing out the sand in your filter:
- There are different types of sand filters, the first step is to open the filter and drain out the water to make it easier to dig out the sand.
- You need to be careful when digging out the sand. The best option is to clean out the sand is to use a plastic cup and not a shovel. There can be some fragile items within the filter that can be easily broken with a shovel or something similar. Remove the underdrain if your unit allows.
- After all of the sand is removed, you will now need to clean and examine the laterals. Check the laterals for signs of breakage and replace any if necessary. If they are impacted with dirt, you can soak them in a mixture of muriatic acid and water. (Note: make sure that you add acid to water and not water to acid.) Rinse the laterals thoroughly after they have been soaked in the acid mixture.
- Clean out the tank and re-install the clean laterals.
- Now it is time to replace the sand in the filter. Replace the underdrain, where applicable and add water until the tank is half-full. The water will help protect the laterals as new sand is added. As each bag of sand is added, you will need to level out the sand within the unit. Refer to the amount of sand that is recommended by the manufacturer on the label of the tank.
- Finally, you will need to reassemble the filter and restart the system in the backwash mode. This will help with flushing the dust from the sand.
If you experience issues, please contact a pool professional for more in-depth assistance with your unit.
A cartridge filter should be cleaned at least twice a year. If you clean your filter cartridge four times per year, you can extend the life of the cartridge elements. A cartridge filter does not require continuous maintenance and backwashing. The process to clean a cartridge filter is simple, but it can take a bit of time.
- Refer to the manufacturer’s directions before you start taking apart and cleaning the filter or take a photo of your unit to a local pool retailer for assistance.
- Shut the system down and start to bleed the air from the filter.
- The clamp that holds your filter together will need to be removed. Once the clamp is removed, you should be able to take off the top portion of your cartridge filter.
- Carefully remove the cartridge elements from the unit (there may be a part holding the filter in place). Check each cartridge for potential wear and damage. If you find any cracks in the plastic housing or damage to the filter, you should replace the filter cartridge. Any type of damage can lead to a less efficient system.
- Rinse off the loose debris from the filter cartridge. Be gentle with the water flow as you do not want to cause damage to the filter while cleaning it.
- Use the recommended filter cleaner by the manufacturer or by your local pool retailer. Follow the instructions of the filter cleaner found on the packaging. The filter cleaner should remove the compounds that block the dirt from sticking to the filter.
- Rinse the cleaner once again to remove any chemicals and additional debris.
- Once all of the filter parts are clean, it is time to reassemble the filter. Pay attention to the parts of the filter and make sure none of them need to be replaced as well.
- Turn your unit back on and open up the air valve at the top of your filter to remove any excess air in the system. Refer to the pressure gauge at the top of the filter, to make sure the proper pounds per square inch (PSI) is correct for your unit.
If you experience issues, please contact a pool professional for more in depth assistance with your unit.
DE Filters can filter the finest of particles but do require occasional backwashing and monthly cleaning. When you notice that your pressure gauge is 8-10 pounds per square inch over normal starting pressure, it’s time to be cleaned. A DE filter contains grids that hold the DE (Diatomaceous Earth) and the grids function as a screen that captures that dirt and other particles.
- The first step in cleaning your DE filter is to backwash it. This will clear out the dirt and debris in the filter.
- You will then turn the pump off and drain the water from the filter tank by removing the plug.
- You will then open the DE filter and remove the grids. Rinse off each grid, flushing off the DE. Then rinse the rest of the tank and remove the O-rings from the filter.
- Replace the grids into the filter and lubricate each of the O-rings.
- Before adding DE back into the tank, you will need to turn the filter back on.
- Add more DE through the pool skimmer. The amount that you will need to add will depend on your filter. Be sure to check with your pool filter manufacturer’s instructions to determine how much DE to add back into the filter.
As always – be sure to consult a pool professional if you have any questions.
Cleaning Pool Filters
Clean your filters. This may be necessary after a heavy storm or once every few months depending on conditions in your pool. It would be best to clean them about every 4-6 months. Just remind yourself to do it each time you come back from the dentist, or each time you change the air filters in your home, which should be about the same frequency. If you have an extra set of elements it is a much easier and quicker job. Soak dirty filters in a 10% solution of muriatic acid or a solution of TSP (trisodium phosphate). Use a rubber trash can. Wear gloves and eye protection. Be careful! Always add acid to water, NOT water to acid. Rinse until clean and let them dry. Put your supplies away until your next swap-out.
Salt Generator Cleaning
If you have a salt water chlorine generator then you will need to check and clean the blades in the unit about every 30 days. If the red flow light or flow meter is on or reading less than normal, then the blades are likely calcified and producing little to zero chlorine. Turn off the pump, bleed off any pressure, undo the unions and clean the blades per the manufacturer's recommendations.