There’s perhaps no other feeling that feels as good as entering into a hot tub after a stressful day’s work. Warm water can help you relax and unwind, as well as help you loosen up your muscles that have gotten stressed over the day. However, this experience is enjoyable only as long as the water is clean and free of all impurities. You have your hot tub filter to thank for that. This filter is going to be the key focus of this article, as we discuss the ways in which you can clean it, How to Clean Hot Tub Filter? and help you maintain your hot tub for the long run.

Clean Hot Tub Filter

Many times, the dirt that you carry, along with your lotions, make-up, soaps, and gels also enter the water in your tub. When all of that mixes with the water, it makes the hot tub quite dirty. Your hot tub filters ensure that this does not happen and that all the impurity is filtered out while you get the best and the most relaxing experience. This is why a filter is really important.

Cleaning the filter is something that every hot tub owner must know about, and is an activity that they ought to perform very frequently so that there is no clogging and no damages. When you buy a hot tub, you should know that it requires regular maintenance and upkeep and that it will take some effort on your part.

Over the course of this article, not only shall we discuss the best ways in which you can clean your hot tub filters, but also take a detailed look at everything that you need to know about hot tub filters – what are they, what are the benefits, how do they actually work, and most importantly, how to keep them clean. By the time we reach the end of this article, you’d be a pro at cleaning your filters.

What Are Hot Tub Filters

These hot tub filters and spa filters are basically that component in your hot tub that ensures that your water is clean at all times. Given that so many people love to use their hot tubs outdoors, and people apply all sorts of hair products and skin products, there’s always some unwanted element that is going to enter your water – and nobody wants to sit in dirty water!

When your water passes through a filtration system, it ensures that only pure water is allowed to pass through and all the impurities are filtered away. You can imagine this to be quite similar to how an air purification system works in your room – as air passes through it, it absorbs all the impurities and releases fresh air. A hot tub filter does the same thing – but with water.

Also just so that you are not confused, hot tub filters and spa filters are basically the same thing and are terms that are interchangeably used. Apart from having a good filtration system, hot tub owners are also advised to make use of sanitizing solutions that are flowing in their tub, so that any bacteria, virus, or other unwanted pathogens can be neutered.

thermospas hot tub filters

Importance of Clean Hot Tub Filters

Your tub filters need to be cleaned frequently. This is essential because of the following reasons:

First of all, it leads to water getting dirty. If your spa filter isn’t working properly, it means that your water will continue to flow with all the impurities and contaminants and will appear muddy or murky. That water is neither clean nor relaxing. You might end up coming out dirtier than when you went in after spending a while in the tub.

Next, if you don’t clean your filters on time, they become clogged and stop working. This is so bad that it can be compared to putting yourself in a puddle of dirty water. An effective filtration system keeps things clean and keeps the water flowing. Clogging of the filter also leads to reducing the flow of water and you get an FLO error. A slow flow can also lead to your heating systems slowing down or stopping.

Lastly, if your filter is dirty and clogged, it can lead to the debris getting inside the pump, heater, or other parts of the hot tub and thereby causing them to malfunction as well. Given that hot tubs by themselves are quite expensive, you’d want to ensure that this does not happen and you don’t have to pay extra to get these parts repaired because of debris in the spa filter. These are the reasons why you must clean it often.

How to Clean Hot Tub Filters

Many manufacturers and info-websites will tell you that you need to clean your filter every two to three weeks. However, that information is not adequate enough. There are three types of cleanings that you need to perform at three different time intervals – doing this will help you keep your filter clean and will ensure that you do not have to worry about damaging your hot tub.

First of all, every 10 days, give your hot tub filter a simple cleaning – i.e. wash it with plain water. These filters usually have pleats and scales, which you need to spread out and clean from the center. Give it a strong spray and wash it under running water. This helps with the basic upkeep of the filter.

We also suggest you get hold of a filter cleaning chemical and spray your filter with it once every month. This has to be done on a monthly basis and not too frequently else you might end up damaging the filter more than cleaning it. Once you’ve sprayed the filter with the chemical, allow it to rest for 15 to 20 minutes, and then give it a thorough rinse as you’d do in the 10-day cycle.

Last comes chemical soaking, this is something that you’d do every four months or so, and this requires you to soak the filter in a chemical solution overnight. This is meant to weaken the strongest of debris which tends to stick to the corner and is often not visible to the eye. This will ensure that your filter is as good as new after that.

Here are some more things that you must keep in mind while cleaning your hot tub filter:

  • If you want to clean just scales or mineral salts on the filter, then you might also try cleaning it in vinegar. This is a quick-fix DIY solution and can work in your favor in case there’s nothing present with you at the moment. Vinegar is a weak acid but your skin is safe when exposed to it, so that is another reason why it is safe to use.
  • If your filter is very dirty and if you think vinegar is too weak to do the trick, you might consider using bleach for cleaning it. However, make sure you are using it only when the filter is very dirty and as a last-resort technique and not something that you’re doing regularly. Using bleach is not good for your skin, and it is bad for the fibers in the filter too, as it can end up damaging them and wearing them out.
  • Some people even tend to use dishwasher detergent to clean a hot tub filter. However, if you are doing this, just make sure that your filter is thoroughly rinsed and that no trace of the dishwasher is left on it because when it comes in contact with water, it can cause your entire hot tub to become soapy if it is not washed away properly.

Suction Filtration vs Pressure Filtration

One also needs to understand filtration mechanisms and filter types. Let us first take a look at the two major filtration mechanisms – suction filtration and pressure filtration and how they are different from one another, and then we shall follow it up by looking at the four different types of hot tub filters.

Suction Filtration

This is a very common type of filtration mechanism that you would see in most modern-day hot tubs. Here, the hot tub filter is located up top and the water comes to it via a bottom inlet. The water gets filtered, with bigger debris being stopped at the prefilter levels and smaller portions getting cleaned by the microfilter. The water, purified, is then passed into the pool via the massage jets.

Pressure Filtration

In these filters, the microfilter is placed in a separate canister which allows a better cleaning and debris-collection mechanism. Instead of being placed before the pump, the microfilter in these pumps is located after the pump, and a floor vacuuming system is present on the bottom which ensures better cleaning of the hot tub by filtering out heavier debris initially. This kind of a hot tub filter is generally seen in larger hot tubs.

Different Types of Hot Tub Filters

As mentioned above, here’s a closer look at the four major types of hot tub filters that one needs to know about:

1. Cartridge Filters

These are the most common types of hot tub filters that you will find. If you are a hot tub owner, chances are that your hot tub also features the same kind of filter inside it. These are filters generally made of fabric, paper, or plastic. They are easy to clean and don’t cost you too much when replacing them. These filters need to be replaced more frequently than most other types of filters.

2. Ceramic Filters

Ceramic filters look exactly the same as cartridge filters when it comes to their exterior look and feel. However, they are made of a much better quality component – ceramic. While filters made out of paper, plastic, or fabric will not last you for a long time, ceramic filters are here to stay. While regular cartridge filters need to be replaced every few months, ceramic filters can go on for years without needing a replacement. As you might have already guessed, they cost more than cartridge filters too.

3. Sand Filters

These filters are generally placed outside the hot tub and are basically sand-filled containers that help separate larger debris by trapping it in the sand. These require to be changed very frequently, almost on a weekly or bi-weekly basis.

4. Diatomaceous Earth Filters

These filters work very similar to how cartridge filters do, but instead of making use of any carbon-filter mechanism, they go for the more eco-friendly approach and make use of fossilized diatoms for the filtration process. These need to be replaced every few months too.

When to Replace Hot Tub Filters?

A basic cartridge spa filter needs to be changed at least twice a year – or once every six to eight months. This needs to be done quicker if you find your filter to be worn out, tattered or too clogged for cleaning. If you are using a sand filter or a diatomaceous filter, you’ll need to replace them more often compared to regular cartridge filters.

The exception to all this, however, is a ceramic filter, which has to be changed once every two years or so, depending on how dirty it has become. These filters don’t wear out and can be cleaned with much better ease compared to the other types of filters.

Hot Tub Filter Pro Tips: Things to Keep in Mind

Now that you know everything that there is to know about hot tub filter cleaning, let us take a closer look at some pro-tips that one should also keep in mind:

The color of the hot tub filter tells you a lot about how dirty it is. If the color is brown or green, it means it is now time to clean it, and if the color won’t lighten even after cleaning, it means that it is now time to discard it.

Cleaning Hot Tub Filters

Using ScumBugs is another pro-tip for hot tub filter cleaning. A ScumBug is basically an oil-absorbing sponge that ensures that this oil won’t reach the filter and it won’t clog it.

As a hot tub owner, we strongly recommend you own two pairs of spa filters at all times! There has to be one for immediate use and another one for emergency usage. You never know when you might have to use one and there should always be some sort of a backup option available to you at all times.

Always try and use spa filters that are recommended by the manufacturer as they know which ones will fit your hot tub the best. Getting an ill-fitting spa filter will be counterproductive and will cause either the dirt to enter the tub or will cause unwanted clogging.

Lastly, during the process of hot tub filter cleaning, make sure that you are not using something that can cause damage to your skin. Always use skin-friendly products to clean your filter, so that even if some of that is not washed off properly, you do not face any adverse effects and always remain safe.

Frequently Asked Questions About Hot Tub Filters

Here are the answers to some of the most common and frequently asked questions about hot tub filters. We have put them together in one place so that you get a better perspective of things before we conclude.

Can I use a Hot Tub Without a Filter?

Can you? Yes. Should you? absolutely not. A hot tub filter plays a very important role in ensuring that the debris in the tub does not reach the inner pipelines and does not end up damaging the rest of the structure. Whenever you remove the filter, make sure that you are not using the tub after that.

How Often Should Spa Filters be Cleaned?

A spa filter needs to be cleaned every 10 days or so with regular water, every 2-3 weeks using chemical sprays, and every 3-4 months using a chemical soaking technique. This ensures that all the debris, even the one that clings on to the corners is completely cleaned off and does not affect

What Happens if I Don’t Clean My Hot Tub Filters?

If you do not clean the hot tub filters, two things can happen – firstly, this is bound to happen in the short run, the filter will get clogged and it will lead to the water in your hot tub getting dirty and not getting cleaned.

Next, the clogged spa filters will lead to a slow inflow of water, which will lead to the heater shutting off or slowing down, and will cause an impact in the pump and pipes which will be performing at a normal capacity – leading to major damages in various parts of the tub. This is something that is totally avoidable if you ensure that you are cleaning your spa filters on time.


We hope that by the time you’ve reached this part of the explainer, you have gained a fair idea about what hot tub filters are, how they function, and most importantly, how to clean hot tub filters, as well as how often to clean hot tub filters. We have even tried and provided you some extra bits of information about these filters, tubs, and the different filtration mechanisms which every hot tub owner needs to know about. If you have any more questions or doubts, feel free to let us know over the comments or drop us a mail and we shall get back to you as soon as we can!