My salt water pool has a Sta-Rite cartridge pool filter system so it’s the type I’m most used to.
A cartridge pool filtration system is a popular choice for salt water pool owners given the relatively low maintenance, high level of small particle removal and medium level price. On the other hand, cartridges cost several hundred dollars to replace and regular rinsing of cartridges is required to remove contaminants.
Let’s take a closer look at using a cartridge filter system for your salt water pool, the pros and cons you can expect and how they compare to other filter options.
Salt Water Pool Filter Cartridge Pros And Cons
Here are pros and the cons of a pool cartridge filtration system.
| Pool cartridge filter pros | Pool cartridge filter cons |
| Relatively low maintenance and easy to operate. | Relatively large up front cost for the filter unit and cartridge(s) compared to sand filters. |
| No back washing required with a cartridge filter system which means less wasted water and less work on your part. | Cartridges can cost several hundred dollars to replace depending on the model and brand. |
| Better at removing small particles than sand filters. | Filter mediums (cartridges) need to be replaced every 3-5 years depending on usage, maintenance and product quality. |
| Medium priced and cheaper than D.E. filtration systems. | Can’t remove particles as small as those removed by D.E. filters. |
| Can reduce chemical usage since there is no water drained as with sand and D.E. filters that require back washing and thus chemical replacement as you replace the lost water. | The larger the pool, the more difficulty you can have finding a large enough cartridge pool filter system. |
| No regular replacement of filter medium (cartridges last 3-5 years typically) whereas sand filters require topping up and replacement of sand and D.E. filters require replacement of carcinogenic diatomaceous earth material. | Cartridges need to be rinsed several times per season and especially after an algae bloom. |
How often should you rinse your filter cartridges?
Your filter cartridge system will have a pressure gauge and your system may give guidelines as to when to rinse the cartridges once the pressure reaches a certain level. The more the cartridges hold contaminants and debris, the higher the pressure will go and the less able your filter will successfully hold and remove debris from the water.
At that point, the cartridges will need to be rinsed very well. The good news is that unlike sand filters which are typically back washed monthly, a cartridge filter might need 1-2 rinses per year in my experience. Back washing involves draining hundreds of gallons of water through the filter into your storm sewer to clean out the waste. There is no back washing with cartridge filters.
You can also soak your cartridges overnight in a large bucket with water and a bottle of filter cartridge cleaner added. A good quality filter cleaner will help to remove oils and other contaminants that the cartridges have collected that will impair its effectiveness but may not be visible to the naked eye.
Think of the things brought into the water every time someone jumps in: Bodily oils. Sunblock. Deodorants. Body sprays. Hair. Sweat. Urine. Feces (yep). And so on. If your pet jumps in the water, they’re bringing contaminants in too.
All of these can attach themselves to the cartridges and need to be cleaned off.
What will you typically find in between the cartridge pleats when rinsing them?
The pleats of the pool filter cartridges will often be full of a black mushy substance which is dirt, soil and other debris that has caked together and is obviously wet. Depending on the model and filter manufacturer, you might be advised to simply hose off the pleating but you may also be advised to use another method to remove this gunk.
In my experience, even a strong hose doesn’t always get rid of the gunk that is stuck at the back of the pleating on its own. The cleaner you get the cartridges, the better the results for you the pool owner.
After an algae bloom, don’t be surprised if the previously white pleats of your cartridges are a shade of green. This is the algae that has been attracted to the pleats and it needs to be removed.
When you rinse your cartridge filter system, it’s also a good time to hose out the actual filter housing as well. When you take the cartridges out, take a look at bottom of the housing. I usually find a pile of sand, perhaps a dead worm or two and other debris that should be removed.
Depending on the model, your filter system probably has a screw valve cap that can be removed so you can hose the filter housing out to remove the sand and have the water drain out of the valve onto the ground.
You might be surprised at the amount of sand and silt you find sitting at the bottom of the filter housing.
And remember: When you see really dirty cartridges, it means it’s doing its job and removing this stuff from the pool water you swim in!
How often should you replace your filter cartridges?
I’ve found that cartridges need to be replaced every 3-5 pool seasons. If you take care of them and rinse them as needed and don’t damage them, you might be happy to learn they last longer.
It also depends on what conditions you face in your local area. Algae blooms really clog up the cartridges and you’ll see what I mean when you view the green mush all over the white pleating.
Using a quality filter cleaner every so often can also help to remove the aforementioned bodily oils, grease, sunblock and other contaminants brought into the water.
Summary
You can use the same filter system for your salt water pool as with any other pool system. The main pool filter systems available are sand filters, cartridge filters and D.E. filters. They are listed here from least expensive to most expensive and also in order of how effective they are at removing small particles from the water. So sand filters are least capable and D.E. filter are most capable.
That puts cartridge filters in the middle in terms of both price and their ability to remove small particles which is why they are a very common and popular choice these days for salt water pool owners.
