Every swimming pool out there has a filter. The filter system is a circulating pump that pulls the water out of the pool and runs it through a filter to remove dirt and debris before returning it to the pool. The three most common types of pool filters are sand, diaotemaceous earth (known as DE), and cartridge filters. Pool filter cartridges provide the finest particulate reduction and require significantly less maintenance than the two media filters.
John Woodard, our Master Water Specialist, will guide you on how to keep your pool filter cartridge system properly maintained and your pool water nice and clear.
How do I find the right replacement cartridge for my pool?
If you have a pool filter cartridge system, selecting the filter cartridge is fairly simple. Just like your refrigerator filter, you only have one specific size and configuration that's going to work. However, there are several manufacturers that will make a filter cartridge that will fit in your pool filter, so you want to make sure you get one that's high quality.
What size pool filter cartridge do I need?
The size of your pool is going to determine the size of your filter system and your pump size.The bigger the pool, the more water moving through the pool filter throughout the course of a day.
Optimal cartridge filter for pool size
| Pool Gallonage | Pump Size | Recommended Filter Size |
| 10,000 | 3/4 HP | 100 Sq Ft |
| 15,000 | 1.0 HP | 150-200 Sq Ft |
| 20,000 | 1.5 HP | 300-400 Sq Ft |
| 25,000 | 1.5 HP | 300-400 Sq Ft |
| 30,000 | 2 HP | 400-500 Sq Ft |
| 35,000 | 2 HP | 400-500 Sq Ft |
| 40,000 | 2.5 HP | 500+ Sq Ft |
| 45,000 | 2.5 | 500+ Sq Ft |
Does micron rating matter?
If you have a media filter, like sand or diatomaceous earth, you can expect mechanical filtration of around 25 micron. To put that in perspective, if you cut a human hair and look at the diameter of the end, that's about 75 to 80 microns, so 25 microns is getting down to the point where you might not be able to see a particulate with your human eye. A cartridge filter provides filtration between 10 and 15 microns, allowing you to clarify an even finer particulate out of your swimming pool.
Advantages of pool filter cartridges
Not only does a cartridge filter provide a finer micron particulate, but they are much less maintenance than the media filters like sand and diatomaceous earth. Also, when the media filters backwash, they move water out of your pool to the drain that you then have to replenish. With a cartridge based filter, your pool is not losing any water because it is not backwashing.
- Finer micron reduction
- Less maintenance
- No backwashing or water loss
How to maintain a pool filter cartridge
How long do pool filter cartridges last?
The lifespan of your pool filter cartridge is going to depend upon how much water goes through the filter, how much care you put into your pool's maintenance, and how much dirt gets into your pool. For example, always rinse your feet off before you jump in. A lot of those kinds of practices can drag dirt and debris into the pool. This will end up on the cartridge filter.
To maintain a pool filter cartridge, you will periodically have to take it out and clean it. The more you invest in maintaining a clean pool, the less often you will have to clean the cartridges.
Does sunscreen affect the pool filter?
Another thing to consider about filter life is the use of oils. Suntan lotions and tanning oils are going to manifest on your filters as a film. It will build up quickly if you don't keep it in check. If you are lathering up your kids with lots of sunscreen, the filters are going to have a little shorter life.
When do I clean my pool filter cartridge?
One indicator you can always look to is the pressure gauge on your filter system. The higher the pressure, the more resistance the pump is having pushing water through the the filter cartridge. When the pressure gets high, it's time to take it out and clean it.
How do I clean my pool filter cartridge?
You can clean it by simply rinsing it off with the garden hose. Sometimes you may need to take a brush to it, but when you put a brush to the filter, you will erode some of that material. Over time, if you brush it off frequently, you will knock holes in the media and destroy the filter. You can only do that a couple of times before you should replace the cartridge.