How to choose between the right filter cartridge for your spa

How to choose between the right filter cartridge for your spa - Click to enlarge

To enjoy your spa safely in crystal clear water, you need a good filtration system. A filter is essential to keeping your water clean, as it catches particles as small as 20-30 µm (1 µm = 1 micron = 0.001 mm) and retains them in the folds of the fabric until the filter is rinsed.

Many filter manufacturers have created their own filter cartridge references for the most common models sold on the market (for example PWW50, PRB50 or PRB25 filters).

If you are fully satisfied with your filter cartridge and you find its reference on our site, we advise you to continue to buy the same brand. And if you are a little lost with all the different brands and their ranges with often noticeable price differences, this page is here to help you. We sell a wide range of brands and sizes of filter cartridges on our site, all of excellent quality, but with different features and technologies. We'll explain everything so you can find your way around and choose the best filter for your needs.

The different brands and technologies sold by tubs parts

Proline and Darlly

Proline and Darlly filters are made with Reemay fabric, which is specially designed for pools and spas, made of reinforced synthetic fibres and is chemical resistant. This fabric uses continuous filaments so that it does not fray and tear. The filters have a good dirt holding capacity, and can operate for a long time between each wash.


The original brand for most spa filters, Pleatco has been manufacturing filters in the United States for over 40 years. They use a spun-bonded polyester fabric that is "bonded point", i.e. with links between the fibres at regular intervals. This technology gives a small cell texture to the filter surface, and allows more water to pass while catching more particles, and especially finer particles than other filtration fabrics. This fabric contains more fibres per unit area than standard filters, and allows easier rinsing.

Acclaimed by the team, Pleatco cartridges perfectly replace all your filter cartridges, especially ones from Unicel.

Antimicrobial filters

Since hot water is a breeding ground for bacteria growth and proliferation, filter brands offer for some of their models a fabric with a continuous action against microbes: the anti-microbial series from Pleatco, and Microban from Proline and Darlly.

During the manufacturing process, an antibacterial material is diffused into the filter core, which continuously prevents the proliferation of bacteria on the filter surface. The fabric imbued with the antimicrobial material therefore consists of a hygienic protection preventing the proliferation of harmful microorganisms such as bacteria, mould and fungi that can produce stains, create odours and cause general deterioration of the filter.

On Pleatco filters, the tips are also made of highly resistant, antimicrobial plastic. Finally, Darlly offers the Silverstream range, which, in addition to using a Microban fabric, incorporates antimicrobial prevention technology based on silver ions incorporated in the upper and lower filter tips and in the filter core.

Manual cleaning is always essential

We remind you that the more you use your spa and the hotter your water is, the faster your filter will clog. It will therefore be able to filter less and less the impurities in the water. If you notice a decrease in the discharge flow, it is time to clean your filter. We recommend monthly tap cleaning, or more if your filters are small or if you use your spa intensively.

For a degreasing of oily residues, a cleaning of your filter is recommended every three to six months by soaking it for a few hours, or even an entire night, in a filter cleaner. If you notice a discoloration of your filter (going from white to grey and/or brown), it is high time to degrease it.

With proper maintenance, your filter cartridge has a life of one to two years. If you notice a reduced dirt retention capacity, a less compact or even relaxed fabric, it is time to change your filter cartridge.