Pool filters can remove all sorts of debris from your pool. When the filter ages, it can’t remove as many algae and other contaminants. Failure to replace your pool filter will result in clogged plumbing, bacterial blooms, cloudy water, and more. There are plenty of early signs that it’s time to replace your filter, though.
Pool filters last between 8 to 12 years. You can make your filter last longer by cleaning it regularly, backwashing the sand or DE, and replacing the cartridges and fins if they tear. Your pool filter should have the same GPM (gallons per minute) as your pump to prevent excessive pressure buildup.
In this post, I’ll discuss how long your pool filter should last, how to make it last longer, and how to know if it’s time to get a new filter.
What Is the Life Expectancy of a Pool Filter?
Pool filters should have a life expectancy of about a decade. However, the filter’s manufacturer, band count, and maintenance schedule affect how long it lasts. Excessive amounts of algae and other debris will also influence the filter’s longevity.
If your pool keeps turning green, it could be because your filter’s life expectancy is coming to an end. Some filters have leaks, cracks, and other issues that shorten how long they last. However, you don’t always have to replace the whole filter if the media has issues. Most filters go through several media changes before the filter needs to be replaced.
How Long Do Pool Filter Cartridges Last?
Pool filter cartridges last between two to five years. Most manufacturers list how long they expect their cartridges to last. Check the pleats, bands, and caps for signs of damage. If anything is torn or disconnected, it can’t be repaired and must be replaced.
Here are the three things you should know about replacing filter cartridges:
- One broken cartridge prevents the rest of them from working properly. Your pool filter will remove fewer particles. This process puts the other cartridges on overdrive, increasing the chances of tears and breakages. Replacing the damaged cartridge will improve the other cartridges’ performance.
- Make sure the cartridges are connected to the manifold. Every multi-cartridge filter has a manifold that holds all of the cartridges in place. Look for manifold cracks. If it’s cracked, it’ll leak debris into the pool and ruin the cartridges. Firmly push the manifold on the cartridges until it’s all the way in.
- High-end cartridges last much longer than low-budget cartridges. Single-use or generic brand cartridges shave several years off your filter’s lifespan. I suggest always using the manufacturer’s recommended cartridges. You’ll spend more upfront, but you’ll save a lot of money in the long run.
Keep in mind that some pools use one-time cartridges. For example, Intex and Bestway filters often come with single-use cartridges that only last two to four weeks. If you wash and reuse these cartridges, they’ll break apart and damage the filter.
How Do I Know If My Pool Filter Is Bad?
To know if your pool filter is bad, look for these signs:
- Look for cracks on the filter’s tank. Cracks are surefire signs that it’s time to get a new filter. A broken filter tank typically costs close to the same as a new filter. The tanks are quite durable and are undoubtedly the most expensive part of the filter. Cracks typically happen around the unions and body rings.
- Inspect the filter’s internal components. There are several parts in all pool filters. For example, the manifold, air relief system, center pipe, laterals, and other parts are susceptible to breakages. If any of these components break, they’ll reduce the filter’s effectiveness. All broken parts have to be replaced, not repaired.
- Check how old your filter is if it won’t clarify the water. Some filters lose their functionality from natural wear and tear. If your filter is older than seven years, it’s time to look for a new one. You can get a filter with the same footprint, which means you don’t have to cut the plumbing to change the unions.
- Find out if your filter can’t hold the filtration media. If you have a sand filter or DE filter, there shouldn’t be any media in the water. Loose media is a sign of broken internal parts. Make sure the laterals and center pipes are secured to their respective threaded fittings. Loose parts slowly crack the filter tank.
- Learn if your filter is the right size for your pool. Every filter should have the right square footage, GPM (gallons per minute), plumbing size (I recommend not using adapters if possible), and filter media size. Using the wrong size can shred the filter’s components and cause cavitation.
Once your pool filter goes bad, your pool will look cloudy, and the algae won’t come out. You can kill the algae blooms, but the filter can’t remove the dead spores. You’ll end up with a white pool that won’t clear up. The good news is that there’s a lot you can do to get the most out of your pool filter.
How Often Should I Clean My Pool Filter Cartridge?
You should clean your pool filter cartridge every one to three months. However, some cartridges get dirty quicker than others. Rather than relying on a cleaning schedule, I suggest cleaning the cartridges when the filter’s pressure gauge exceeds 25 PSI. Replace any cartridges that have broken bands or torn pleats.
If your cartridge has tears or broken caps, it’s time to get a new one. Review our list of the best pool cartridge filters if you need to get a new one. It’s worth getting a filter that will last longer if it costs a little more. Make sure your new filter comes with a warranty.
How to Make Your Pool Filter Last Longer
To make your pool filter last longer, try this method:
- Clean or backwash your filter whenever the pressure meter is over 25 PSI. The pressure gauge lets you know if there’s too much PSI in the filter. When the filter gets over 25 PSI, there’s a high chance that it won’t remove any debris from the water. Furthermore, it can damage the filter, pump, heater, and plumbing.
- Wash the outside of your filter monthly. Most filters are made with fiberglass. If you don’t wash the filter with hose water, the fiberglass will shed and crack the filter. The fiberglass can also get in your eyes and skin, causing extreme discomfort. Some manufacturers let you use dish soap on the filter, but it’s worth asking beforehand.
- Consider getting an annual pool filter service. You’ll save a lot of money in the long run with regular services. Pool professionals can look for loose parts, broken cartridges, and other components. They can also deep clean the filter, making it look almost as good as new. It’s more than worth it for those who want to lengthen their filter’s lifespan.
- Keep air out of the plumbing system. Air in the system will shred the filter. Open the air relief valve to remove as much air as possible. Check the pump lid to see if there are air bubbles. You can also look for bubbles around all of the pool’s inlets and outlets. Minor leaks cause a lot of air problems.
- Make sure you have the correct plumbing dimensions. Your pool filter should have the right unions for the plumbing. For example, if you have 2” plumbing, make sure you have 2” unions. Adapters should be used as a last resort. Most adapters reduce the filtration and pump pressure.
In my experience, you can increase your pool filter’s lifespan by two to four years with these techniques. Most filter tanks last quite a long time; it’s all of the other parts that add up and fail. Maintaining these components will help you save money while keeping your pool as clean and clear as possible.
Why Does Your Pool Filter Get Dirty So Quickly?
Your pool filter gets dirty so quickly because there’s too much algae in the pool, the filter isn’t big enough for the gallon total, or there’s a lot of debris in the water. Consider getting a solar blanket to keep debris out of the pool. You can also use a water clarifier to deep clean the pool and prevent long-term filtration problems.
If your pool is always dirty, the filter might be the wrong size. Small filters are cheaper, but they don’t remove enough debris to keep a mid-sized pool clean. Check the manufacturer’s suggestions to know what size filter you should get for your pool.
Another reason you should get the correct filter size is that too much water pressure will destroy a small filter. For example, if you have a large pool and a high-end pump, a low-quality filter can’t keep up. The internal components will break apart. You’ll likely have to deal with union leaks, too. Proper filter maintenance and longevity start with the filter’s size.
Jonah has worked for several years in the swimming pool industry installing and repairing equipment, treating pools with chemicals, and fixing damaged liners. He also has plumbing and electrical experience with air conditioning, ceiling fans, boilers, and more. When he’s not writing for Temperature Master, he’s usually writing for his own websites, LawnCareLessons.com and DIYByHand.com.