How Does a Hot Tub Filtration System Work?

By Calvin | Last Updated: May 29, 2021 | Guides / Equipment

Have you ever wondered why you hardly notice any debris or solid particles in your hot tub water? Well, that’s because of the filtration system in your hot tub. The filtration system in your hot tub is responsible for trapping dirt and other debris that fall into your hot tub water.

The effects of the filtration system and the sanitizers that you add to the water keep the water in the hot tub clean and safe.

But how does the hot tub’s filtration system work exactly and how is it able to pick the debris that falls into the water? Let’s find out.

We all know how a hot tub works, but how does a hot tub filtration system work? You need to know this because if your hot tub filter is broken then you will know the problem it has.

What Is a Hot Filtration System?

The filtration system of a hot tub is the part of your hot tub that traps dirt and debris like leaves, oils, body care products, and the likes that fall into your hot tub water. The filtration system is usually called the hot tub filters. But the filters just refer to a part of the filtration system.

The filtration system is made up of the core structure which is usually made from thick plastic. The core ensures that the filtration system can stand the force of the water as it circulates through the filter.

Asides from the core, there is the media which is usually made from soft materials like polyester and fabric. This is the part of the filtration system that traps dirt and debris. Then we have the cap. The cap refers to the two plastic discs at both ends of the filtration system. The cap ensures the core and the media stay in place.

Now that you know the parts of a hot tub filtration system, how does the filtration system work?

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How Does a Hot Tub Filtration System Work?

Much like every other part of your hot tub, the filtration system relies on the circulation of water in the tub to work. When the water in the tub is filled and the jets and the circulation pump are turned on, the water begins to circulate inside the hot tub.

The water that is being circulated inside the hot tub passes through the filtration system together with the dirt, debris, and oils that are inside the water. As the water passes through the filtration system, the filters or media trap the dirt and debris, ensuring that the water that flows through the filters to the heater is clean and dirt-free.

Think of the filters as a sieve that only allows only clean water to pass through. The higher the amount of water that passes through the filtration system, the cleaner the water will be. For the filters or media to cope with the turbulent flow of water in the hot tub, the core (a thick plastic) is designed in the middle of the filtration system.

The core strengthens the filters so they aren’t shifted as the water flows through them. The cap then ensures that the core and the media stay in place. All of these components of the filtration system work together to ensure the water is clean and safe. That’s how the filtration system works in your hot tub.

Types of Hot Tub Filters

While there are different types of hot tub filtration systems, there are also different types of hot tub filters. The filters refer to the media that is coated around the core.

This is the part of the filtration system that traps dirt. The filters can be differentiated based on the material they are made from. Here are the most common types of hot tub filters.

Cartridge Filters

Cartridge filters are the most common types of filters in hot tubs. These filters are usually made from paper, fabric, polyester, or a combination of two of these.

The filters are usually placed in a plastic container known as the cartridge and then positioned inside the filter housing. Most pressure-type filtration systems use this type of filter.

Ceramic Filter

The ceramic filters are similar to the cartridge filters, at least in design. The filters are also made from fabric or light plastic.

The main difference is that the filter container is made from ceramic materials rather than plastic. This makes the ceramic filter very durable. Ceramic filters can last up to 5 years and top-quality ones can last longer.

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Sand Filter

This is by far the least common type of filter. As the name connotes, sand filters contain sand. The filters have a spherical shape and they are filled with sand that removes contaminants and debris. Sand filters usually sit outside the hot tub and they usually don’t need that much cleaning.

On the plus side, sand filters are cheap and a pocket-friendly option but on the downside, the filters aren’t durable and become less effective at filtering particles as time passes.

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Types of Hot Tub Filtration Systems

All hot tubs have filtration systems designed in them. But not all hot tubs have the same filtration system. While all hot tub filters trap dirt and debris that get into the water, they each have different ways of going about this. Let’s check out the types of hot tub filtration systems and how they work.

The Suction Type Filtration System

This hot tub filtration system is the most common. Many hot tub producing companies design their hot tubs with a suction-type filtration system. The popular use of this filtration system has earned it the nickname “Industry standard”. The suction type filtration system is usually designed within the hot tub skimmer. The hot tub skimmer is where the hot tub pulls water from the surface.

As the hot tub draws water from the surface through the skimmer, the water passes through the filter basket which removes the large debris and dirt inside the water. The water is then pumped through the microfilter to the jets. The microfilter then picks up the tiny debris that may have been missed by the filter basket. The jets then dispense the water into the hot tub.

The suction type filtration system is usually not expensive which a big plus but they need regular maintenance. Most suction-type filtration systems require the user to remove and clean the filters weekly. Also, the suction type filtration system needs to run for a minimum of eight hours to work effectively and this can skyrocket your electricity bill.

The suction type filtration system also filters the water from the top of the hot tub since it is positioned inside the skimmer. This means any debris that finds its way to the bottom of the hot tub has to be removed manually by the user.

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Pressure Type Filtration System

The pressure type filtration system is an improvement on the suction type filtration system. For starters, the microfilter is not positioned within the skimmer. It is not housed in a separate canister and placed after the pump. There is also the introduction of a floor vacuum. In the pressure type filtration system, the pump draws in water through the skimmer and the floor vacuum.

The floor vacuum and skimmer basket then catch any debris like leaves before it gets to the pump. The floor vacuum and skimmer basket serve as a sieve that blocks any debris from being drawn into the pump.

The clean water that goes into the pump is then forced out through the microfilter which picks up smaller debris and dirt that have been missed by the skimmer and the floor vacuum. The water that comes out of the microfilter is then channeled to flow through the jets into the hot tub.

The biggest advantage of the pressure type filtration system is that it catches more dirt. The floor vacuum and the microfilter work together to ensure there is almost no debris at all in the water. This allows the sanitizers to be focused on the bacteria and germs in the water.

The pressure type filtration system is also faster than the suction type filtration system. This filtration system can clean water in as fast as 15 minutes while the suction type needs to run for hours. This will save cost and energy.

With all these improvements, the pressure type filtration system is more expensive than the suction type filtration system.  This is why this filtration system is not so common. It comes at an additional cost but you can’t say it’s not worth it.

Hi, I'm Calvin Hall, the owner of Hot Tub Wiki. I worked at a local Spa Service for a few years before creating this website. I have owned several hot tubs and fixed a thousand of them. So, I know a thing or two about hot tubs.