Most hot tubs are manufactured with built-in filtration systems designed to remove particles from the water. These cartridges vary greatly in height, diameter, pleat count, pleat material and also the connection type where the filter is attached to the plumbing. 

The vast majority of hot tubs will be fitted with a single filter, although some larger spas will have multiple cartridges to increase the total coverage and the ability to pull more water through the system. This shortens the amount of time it can take to recover the water after heavy usage although each filter will need cleaning regularly.

Manufacturers recommend a hot tub filter should be rinsed down each week and then deep cleaned at least once a month using a filter cleaner such as Immerse Cartridge Cleaner or Rapid Filter Kleen 

Regular deep cleaning of the filter will break up calcium and oils and greases that build up in the pleats, which can then be rinsed down and removed altogether. Once rinsed it is advisable to allow the filter to dry out completely before reuse as this will allow the fibres in the material to shrink back together and maintain optimum filtration performance and also prolong the effective life of the filter cartridge itself. Water filtration accounts for 50% of water sanitation so healthy clean filters are important for maintaining a healthy inviting hot tub.

The expected lifespan of a hot tub filter cartridge can vary dependent on the use of the spa, its location and setting, and also how often the how well both the hot tub water and the filter itself are maintained. Effective life expectancy can also be affected by the size of the filter to water ratio. A typical hot tub used in a family setting, is likely to put heavier use on the hot tub filter than a one used less frequency by one or two people.

When to replace your hot tub filter

Some manufacturers will specify a single small filter for a reasonably large hot tub with a bigger volume of water, which means that the filter media itself is working harder to remove debris and particles form the water. Others use one larger filter or multiple filters to lessen the strain and improve the coverage.

In the average size hot tub of around 7ft square (2.1m), the average volume of water is around 1200 litres. The most common filter sizes such as the Boca and Captiva are 45 to 50 square feet of coverage and so should last around 9 to 12 months effectively dependent on use before needing replacing. Larger filters such as those used in Sundance Spas 780 and 880 series hot tubs, or where multiples are used should last the full 12 months before needing replacing. 

It is always a good idea to carry a spare filter for your hot tub, allowing you to install a clean and dry filter each time whilst the one coming out is cleaned and dried out thoroughly. This will guarantee the best filtration performance and make water maintenance easier.

What if my hot tub has a micro filter? Can I clean my micro filter in the same way as the main filter?

Some hot tub manufacturers use micro filters, made up of a microfibre material, to remove the smallest and finest of particles from the water. Sundance Spas introduced the hot tub industries first Micro Clean filtration system, using a low flow circulation system to drag water through at a slower rate but capturing the smaller particles not taken out by a more standard filter cartridge. 

Micro filters such as the Sundance CAYO Micro One filter are designed to collect particles and absorb them from the inside of the material to the outer layer. Due to the dense nature of the material it cannot be cleaned with a cleaning agent and should simply be disposed of and reopened as per the manufacturer’s recommendations. This will vary so you should seek advice from your main dealer. 

For Sundance Spas the micro filters should be replaced as follows: –

Sundance CAYO Micro One filter – 2 to 3 months

Sundance MicroClean Plus filter – 9 to 12 months (This can last up to 18 months in some circumstances but the average family will gain 12 months effective usage on average).

How often should I change the filters in my LAY-Z-SPA?

Inflatable hot tubs generally contain a small filter for the volume of water and have to work very hard to keep the water clean as a result. Inflatable hot tub filters should be cleaned more regularly, typically each week with a deep soak, and may need replacing at least every two to three months dependent on usage.

Replacement hot tub filter cartridges can be purchased in store or on line at www.myspadirect.co.uk