How to Clean Hot Tub Filters at Home

Easy way to clean a spa filter

Clean hot tub filtersCleaning a hot tub filter is usually as easy as rinsing it off with a garden hose.  Trying to get dirt out of the pleats may involve ruffling the pleats as you rinse them.

Overnight Filter Soak – for that deep cleaning
For a more thorough cleaning, use an overnight filter cleaning solutions that contain muriatic acid.  You can also dilute muriatic acid and use that as the filter bath in a bucket, that eats contaminants up and opens the filter pores again.  

You don’t want to get acid on your hands though, so you may want to wear protetive gloves when working with any kind of acid. Similarly, avoid splashing it in the eyes for obvious reasons.  Or you can purchase a commercial overnight filter cleaner or spray on type cleaner.

Spray On Cartridge Cleaner
Spray on cartridge cleaning solutions apply easily and only take about 10 minutes before you rinse the filter off and can use it again, however you have to wear protective gloves when using the spray and make sure to get it between all of the pleats.  The overnight filter cleaning solution may be easier to use.

Dirty hot tub filter pleats before using a spray cleaner.It is recommended to have a spare filter that can be swapped out as one is being cleaned or even soaked.  That way the cleaned filter can also be allowed to air dry.  Be sure to hose off any filter after it is treated before using in the spa again.

Why Deep Clean the Cartridge Filter?
Cleaning a cartridge filter can extend the life of the filter beyond 1 year or so depending on spa use.  Rinse it off every few weeks and treat the filter every 2 months or so with either an overnight filter bath or a filter spray.

Filter after cleaning with overnight filter solutionSee the difference when you do a deep filter cleaning using either filter spray or an overnight filter soak in a bucket.  The pleats are clogged in the dirty filter, so that even if you rinse with a garden hose, at that stage, oils and trapped particles will not easily rinse out of the filter.

When an overnight filter bath or a spray cleaner is used, the pores  are opened and the filter is ready to clean hot tub water again.

Alternative filter cleansers on the market also include Eco One

Eco One Spa Filter CleanerEco One Hot Tub Filter Cleaner – EcoOne Filter Cleanser

  • Cleans filter without the use of harsh acids or bleach
  • Up to 15 uses per bottle
  • Fast acting, ultra-concentrated formula

Hot Tub Filter Cleaning Devices

Filter FlosserThere are a few devices on the market to make cleaning hot tub filters easier.  The Mikise FFT Filter Flosser Tool Cartridge Cleaning Tool Filter Flosser is a hose attachment that turns the regular garden hose into a wider wand that will clean the width of the filter cartridge as it is rotated.  This shortens cleaning time compared to a regular garden hose, and saves your finger from having to apply pressure on the hose.

filter cleaning device for hot tub filters

The Filter Blaster is a device where you lay the filter down on it and it spins with the movement of the water. 

This blaster device just connects to a garden hose.  It works on most filters under 34″ long but was not rated very highly for some reason.

Complaints depended on local water pressure at the hose and were about some debris still remaining in the filter. 

Learn more about the Filter Blaster by clicking on the image on this page to read some of the reviews.  

It sells for $150 (Model Blaster 3000) but there are simpler versions that sell for around $100 for shorter filters (20″ and 27″ long versions).

There is also a deluxe, complete filter cleaning device where you put the filter inside a capsule and then it rotates automatically and is sprayed at the same time.  Email us if you are interested in more information about this new device.

You can rinse of filters with a standard garden hose, or use a special attachment that makes the spraying easier, but never use a powerful pressure washer directly on filter paper or it can tear the pores and damage the filter media.

 Spa filter cleaner tool cleans any hot tub filter.This spa filter cleaning tool is said to clean any hot tub filter. 

It also has a pleat spreader that holds the pleats apart while the stream of water is allowed to get in between the pleats. 

The Aqua Comb below, in contrast, has longer forks that will get into even the largest pleats.

Just like the other filter cleaning tools, this one also attaches to the garden hose.  This manufacturer recommends using the device every 2-3 weeks when cleaning out the cartridge. 

Don’t know much about this particular one, although any device will hopefully get more water in between the pleats and less water all over you.  Without a filter cleaning device, the process is basically to use a spray nozzle on the garden hose, spray in between the pleats for a good 5 minutes or so.  This works on pool filter cartridges as well as spa cartridges.

If there is enough interest, we may do a “shootout” between the different filter cleaning tools, but all of them do the job better than just by hand.


Aqua Comb PicNew Aqua Comb:

Aqua Comb has 9 little forks that get right into the filter pleats. This simple garden hose attachment makes cartridge cleaning a breeze. Works on both pool and spa cartridge filters.

Read more about Aqua Comb here.

Other ways people are cleaning hot tub filters

Trisodium Phosphate (TSP):  Instead of a commercial filter cleaner, use 1 cup TSP to 5 gallons of water.   Soak for a few hours.  The use of biguanides in a hot tub instead of bromine or chlorine sanitizer will necessitate cleaning it off thoroughly before putting it into any kind of filter bath.  It is a good idea to first rinse of the filter anyways.

Pressure Washer: Not recommended unless you can really dial back the power, because excessive pressure will break and damage the filter paper.

Dishwasher:  First, your filter has to even fit inside of a dishwasher. Some spa filters are so large they may not.  Then you can’t wash dishes at the same time, so you are running the whole dishwasher to clean a filter?  That sounds like a big waste of water.  Why wouldn’t you want to wash the filter along with your fine china?  I don’t know how well your dishwasher cleans your dishes, but I would not want any chemical residue or particulates on my dinnerware and you probably don’t want that either.  The heat drying cycle may melt the plastic and dischwashers may in turn provide the filter with residual soap which may cause foaming in the hot tub.  So dishwasher is not high on the list of best ways to clean a spa filter – do so at your own risk.

Dishwasher Detergent:  Some may use a dishwasher detergent such as Cascade in a bucket.  Again, it will clean to some extent but you can be the judge if it deep cleans as effectively as an acidic type of filter spray or wash.  Still in a pinch, this may work better than some of the other methods and hopefully does not generate any suds.

Bleach:  Most people would agree that bleach will damage the filter paper, so it is not advisable.  You only need to give the filter a chemical deep clean every 2 months or so, so a bottle of that stuff should last you quite a long time. Bleach costs money too and may just do more damage than good.  You spend alot of money buying and operating the tub, so invest a little in the best products for taking care of the spa and change out the filter annually.  That said, anything that opens up the filter pores is better than leaving them clogged. 

Vinegar:  Household products such as vinegar do have cleaning properties. Vinegar and water solutions do a pretty good job cleaning windows as well.  You could put a few cups of white vinegar in a bucket of water and allow the filter to soak. You will still need to rinse off the filter afterwards.  If you don’t mind a little vinegar smell, this may work for mild pore opening.

If the filter is really dirty, nothing beats an acid solution as sold in some of the commercial filter cleaners to get the filter white and open the pores again.

When removing the filter for cleaning, it is best to turn the spa off as you don’t want it circulating without a filter.  Also, the filter is difficult to remove if the pump is on low speed or the circulation pump is active.  Follow the filter care instructions that came with your spa as well.

Cartridge Filter CleanerMethods to Cleaner Water in the Spa

  • clean and rinse the filter regularly
  • deep clean the filter every 2 months with spray or filter soak
  • replace the filter every year
  • use a pre-filter when filling the spa
  • shower before entering the spa
  • rinse of bathing suits before entering the spa
  • monitor pH
  • monitor sanitizer
  • shock treat spa weekly (monopersulfate)
  • assure the cover is in good shape

A clean filter will keep everyone in the hot tub safe while bathing and also protect expensive spa equipment.  A clean hot tub filter allows better circulation of the water, saving electricity as well.  The natural way to clean a spa filter is to hose it off, but doing so regularly can help maintain clean spa water quality.

Why clean a cartridge filter at all?

It saves the equipment and it saves your skin.

As a brand new filter is inserted into hot tub water, it initially does a perfect job of filtering out particulates and also coagulated globs of various soaps, lotions, skin cells, oils, and lotions that are in the water.  The filter media then actually gets even better for awhile and filters even finer particles.  It will reach a point where it can no longer trap new particulates and it takes more pressure to pass water through the filter. The pressure translates into the pump having to work harder.  At that point, the garden hose will once again get rid of larger particles and free up some filtration power.  But the hosing off alone will not get rid of microscopic particles embedded in the filter paper.  That is why periodically an acid cleaning solution is needed to completely unclog the filter pores. A commercial filter spray or overnight filter soak will do the job nicely.  Note that if the filter is not regularly maintained, some suggest to replace the filter every 3-6 months, but if some care is taken, they should last a year or so with no problem.

If you must use a regular spray hose, here is a video on properly cleaning the spa filter .  Try one of the filter tools above, it just may make cleaning the cartridge easier and also do a more thorough job while leaving you a little less wet.

Take care of your filter and your filter will take care of you!