How To Clean Your Hot Tub Filter (3 Different Methods)



Filtration is an important part of keeping your tub water clean.

Sanitizing chemicals in the water start this process by killing off contaminants in the water such as viruses and bacteria. However, a filter is what actually removes them from the tub, so you aren’t soaking in filth.

We’ll teach you how to clean out your dirty filters so they don’t lose effectiveness, which can eventually lead to issues with your water.

Why Should You Clean A Hot Tub Filter?

Cleaning a hot tub filter is non-negotiable.

Sanitizers such as chlorine or bromine do a lot of the heavy lifting when it comes to cleaning the water, but sanitizer only kills the bad stuff, it doesn’t strip the water of things like dirt and debris.

While it does require some physical work on your part, the trade off of not cleaning the filter will be upset water chemistry, and you’ll be scrambling to rebalance and restore the tub.

Left too long, the water may even become so overrun with pollutants that dirty water finds its way into the pump or heater, leading to a host of other issues with your tub.

You may even have to start over by draining the tub and refilling it, which is both costly and time consuming.

How Often Should You Clean The Filter?

Knowing how a hot tub works, cleaning your hot tub filter should become part of your regular maintenance.

You should inspect it a few days after doing a new fill, as the water source you’ve used could have contaminants that the filter has already grabbed. You can alleviate this problem by investing in an in-line filter for your garden hose.

Regular inspection of the filter should be done every 2 to 3 weeks. If you’re using the tub frequently, you may want to lean more to 1 to 2 weeks. Over time, you’ll become familiar with how clean the water stays in relation to how often you use the tub.

Every 2 or 3 months, you should do an in-depth cleaning of the filter. This will add to it’s longevity. Most cartridge filters will last at least a year, provided you care for it properly.

Replacement of the cartridge(s) is usually required somewhere between the 12 and 24 month mark.

How To Clean A Hot Tub Filter

There are basically 3 ways to clean a hot tub filter, all of which are simple and require minimal elbow grease.

Method #1: Give It A Rinse

The easiest road to having clean filters is to start with a rinse.

Rinsing off the filter should be done every 2 to 3 weeks. This proactive measure helps to not only protect the filter from damage, but also keeps it working effectively so your water doesn’t go belly up.

How to clean your filter this way:

  1. Start by cutting the power to your tub.
  2. Remove the cartridge filter. This will either be located in the skimmer/filter basket of the tub, or in a dedicated housing along the equipment chain.
  3. Inspect the pleats and remove any large debris such as leaves and hair.
  4. Use a garden hose with a nozzle and spray it down at a 45 degree angle. This will ensure the contaminants are sprayed off the filter media rather than being pushed through it. It will also protect the filter from water pressure-related damage. 
  5. Inspect it again to make sure you got as much debris off the filter as you could. If not, keep rinsing.
  6. Once you’re satisfied with it, place it back in the skimmer/filter basket, or it’s dedicated housing and close the lid.
  7. Turn the power back on and run the tub.

Method #2: Use An Instant Cleaner

There are cartridge cleaning products that lend a helping hand to keep the cartridge sparkling.

This is usually a chemical that’s sprayed onto the cartridge media and rinsed off to restore it back to a pristine state.

How to clean your filter this way:

  1. Turn off the tub power.
  2. Take the cartridge filter out of its housing. 
  3. Inspect the cartridge for any damage, and remove any large debris that may be stuck in between the pleats.
  4. Apply the chemical product to the filter media. Make sure you follow the instructions on the bottle so the chemical doesn’t damage the filter. You’ll only need to leave the chemical on for a few minutes.
  5. Rinse the cartridge. You can use a garden hose with a spray nozzle, or you can buy a cartridge cleaner tool which shoots water between the pleats. Aim the water down at a 45 degree angle so the debris runs off the cartridge media.
  6. Double check the filter to make sure it’s clean of all debris and that it’s thoroughly rinsed. You don’t want any chemical left on it that could be introduced into the tub.
  7. Put the cartridge back in it’s housing.
  8. Turn the power back on and start up the tub.

Method #3: Deep Soak It Overnight

Every 2 to 3 months, you should schedule in a deep cleaning of the cartridge filter. When it’s subjected to daily cleaning for long periods of time, no amount of rinsing will be able to remove the gunk that’s caked onto the filter’s media.

For this process you’ll need a plastic bucket that can hold the entire filter, as well as a deep cleaning product specific to hot tub cartridge filters.

Some people prefer to use a 50/50 solution of white vinegar and water, which can help you save money by not using more expensive products.

How to clean your filter via deep soak:

  1. Shut off the power to the hot tub.
  2. Fill up your bucket with warm water and add in the cleaner. If using a product, consult the directions on the bottle as dosages will vary.
  3. Remove the cartridge from it’s housing and place it into the bucket.
  4. Let it soak overnight.
  5. The next day, remove the cartridge from the deep soak and hose it down. Rinse thoroughly!
  6. Place the cartridge filter back in its housing.
  7. Turn the power back on and run your tub.

Common Filter Cleaning Mistakes

Not everyone wants to follow the rules of filter cleaning. Here are some common mistakes people make when trying to cut corners.

  • Don’t put it in the dishwasher. It might sound ridiculous, but this is an all too common way that people try to clean their cartridges. Not only can detergents, high heat, and high water pressure damage the filter, but the media will be coated in detergent residue that will be sent into the tub.
  • Avoid using bleach. Diluted bleach is sometimes used to clean hot tub shells, but you shouldn’t use it on your filter. Bleach can seriously damage the fibers on the filter, and you’ll have to replace it soon thereafter.
  • Don’t use household cleaners. If you’ve thought about using a mild dish soap on your filter, think again. No matter how much you rinse it, there’s a high chance soap will remain locked into the filter’s fibers. This can cause a foamy hot tub, which you’ll eventually have to drain to restore the water.
  • Be careful when rinsing. The fibers on filters are delicate, and some nozzles can put out serious power when rinsing. If you blast the water directly at the pleats, you can damage them. For this reason, aim your nozzle down at a 45 degree angle. This will protect the pleats from damage, and will also push any debris toward the ground, rather than through the fibers.

When To Consider A New Filter

There will come a day where no matter how much rinsing and deep soaking you do, the filter will no longer be effective.

You’ll know this when the tub’s water chemistry is difficult to balance, your water remains visibly dirty, and you start to see the formation of scum marks on the inside of the tub (at the water level).

Another big clue is the amount of time you’ve been using the filter. If you take care of it properly, you should get at least a year of use from a cartridge filter, but if it’s compromised in any way, it could be considerably less time.

If the filter media is torn or imploded, or its end caps have become cracked and discolored, it’s time to replace the cartridge. The good news is they’re extremely affordable.

That’s A Wrap!

Keeping a clean hot tub filter is no difficult task.

By following a regular maintenance schedule, and checking up on the condition of the filter itself, you should have minimal problems with filter effectiveness, and it should last you several months.

Categories: Hot Tub Care, Hot Tub Equipment