Ask any hot tub owner what their least favourite part about owning a hot tub is and the answer will likely have something to do with maintenance. Whether you’re talking about adding chemicals, cleaning the shell or having to replace the water, nobody likes hot tub maintenance.

What’s the key to reducing maintenance? It all comes down to the filtration system. Hot tubs with good filtration systems keep the water clean and clear with little required maintenance. Hot tubs with poorly designed filtration systems, on the other hand, require almost constant attention.

To better understand the differences between good and bad filtration systems, let’s first take a look at how hot tub filtration systems work.


Most hot tubs today come with what is known in the industry as a “suction-side” filtration system. In a suction side system, a “skimmer” is installed on one of the side walls of the hot tub, at the water line. Water is pulled into the skimmer by the hot tub pump, where large debris like leaves are trapped inside of the “filter basket”.

Underneath the filter basket is a microfilter which filters out fine debris and helps to keep the water clear. After going through the microfilter the water then passes through the pump then back out of the jets.

This filtration process is done automatically with pre-programmed “filtration cycles” that typically run anywhere from 4-24 hours per day, depending on how efficient the system is able to remove debris and clean the water.


The main drawback with these systems is efficiency. In a suction side filtration system, only the water that goes through the skimmer is actually filtered. This means that it takes a long time for them to properly filter all of the water in a hot tub.

In order to properly filter the water in a hot tub, suction side filtration systems need to run a minimum of 8 hours per day, with most requiring 12-24 hours per day. The longer these systems run for, the higher your energy costs become. While you could simply program the hot tub to filter for less time, you then run into water clarity issues that require a lot of effort and chemicals to clear, leaving you stuck in a battle between higher energy costs or more maintenance and chemical costs.

Another drawback of the water only being skimmed at the surface is that any heavier debris like sand will fall to bottom of the hot tub. This heavier debris then needs to be manually removed.


As you can see, suction side filtration systems can leave a lot to be desired. With this in mind a Canadian hot tub and swim spa manufacturer – Hydropool Hot Tubs and Swim Spas – developed a unique filtration system that became known as “Self-Cleaning” filtration.

Self-Cleaning filtration is built using an ultra efficient system developed for pools and commercial hot tubs. This system differs from suction side filtration in a few ways.

  • The microfilter is taken out of the skimmer and placed in a dedicated canister.
  • The microfilter is placed after the pump (on the “pressure side” of the pump).
  • A floor vacuum is added to the bottom of the hot tub.

The biggest change in this system is that the water now flows from the pump to the filter, rather than water flowing from the filter to the pump.

With Self-Cleaning filtration, water is drawn into the pump through both the skimmer and floor vacuum. These catch any larger debris – like leaves – that might damage the pump. Water then flows through the pump and is forced through the microfilter under pressure. The microfilter catches the smaller dirt and debris, and clean water is returned to the hot tub through the jets.


Self-Cleaning’s biggest advantage is its efficiency. In fact, Self-Cleaning filtration makes it possible to filter all of the water in the hot tub in as little as 15 minutes! This reduces the run time of the filtration cycles to just 2-4 hours per day; saving you a ton of money in energy costs while also improving the look and feel of your water.

This great efficiency comes from placing the filter after the pump. This ensures that 100% of the water that enters the filtration system is filtered, rather than just the water entering the skimmer. The built-in floor vacuum also allows the hot tub to filter out heavy debris like sand, eliminating the need for you to manually vacuum the hot tub.

Self-Cleaning filtration is able to filter so effectively that it also reduces the need for chemicals. Not only does this save you money in chemical costs, it also means that you won’t have to drain and refill the hot tub as often.

Hot tubs need to be drained when too many “dissolved solids” are introduced into the water. These dissolved solids are mostly minerals that get into the water both from bathers and from chemicals. By reducing the amount of chemicals that you add to the water, you also reduce the amount of dissolved solids in the water, meaning less water changes.


As good as Self-Cleaning filtration is in hot tubs, it is even more important in swim spas. Today, most swim spa manufacturers use standard suction side hot tub filtration systems in their swim spas. This is a big mistake. While suction side filtration systems are okay in smaller tanks of water (like in hot tubs), in larger tanks of water (like in swim spas) they’re seriously underpowered.

As we previously mentioned, it generally takes between 8-24 hours for a suction side filtration system to properly filter the water in a hot tub. This number changes depending on the size of the hot tub and the quality of the filtration system itself.

Swim spas are generally between 3-5 times larger than a standard hot tub, meaning that at best you will have to run your filtration system 24 hours per day to keep the water clear. At worst the system won’t be powerful enough to properly filter the water in the swim spa and you will have to compensate with manual cleaning, increasing the amount of chemicals that you add, and draining and refilling the swim spa more often.

The Self-Cleaning filtration systems found in Hydropool swim spas, on the other hand, are able to filter the entire swim spa in 45 minutes or less! Just like in hot tubs, this amazing efficiency means greatly reduced running times, lower energy costs, less needed chemicals and less draining.


While often overlooked by most people, the filtration system is perhaps the most important component of a hot tub or swim spa. Poorly designed filtration system cost much more to run and require more maintenance than one with a well designed filtration system. Not only that, hot tubs and swim spas with poor filtration are also much more susceptible to problems such as cloudy or green water. These problems not only cost money to fix, they also cost time as you are usually not able to use your hot tub or swim spa while fixing these problems.

At The Spa Shoppe we are proud to sell Canadian made Self-Cleaning hot tubs and swim spas from Hydropool. Although more expensive than traditional suction-side filters, Self-Cleaning systems run at a fraction of the cost and require much less maintenance than suction-side filtration systems; more than making up for the difference in purchase price!

While all hot tubs and swim spas clean themselves, only Hydropool Hot Tubs and Swim Spas have a true Self-Cleaning filtration system!

The Spa Shoppe

(905) 666-5333

1545 Dundas St E
Whitby, ON L1N 2K6



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