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Pool & Spa Filters

 

Why?

A swimming pool filter is like the kidneys of your body.Both require a suitable pump to deliver an adequate water flow through them to enable satisfactory filtration. A correctly sized and operated swimming pool filter will provide the most cost effective method of ensuring clear, clean and healthy pool water.

In Australia there are essentially two types of filter systems available, Sand Filters and Cartridge Filters. Each have pros and cons and the choice for either is both personal and/or job specific.

 

How They Work

A pool filter relies on the pump to deliver the correct amount of flow to ensure optimum effectiveness in removing debris and impurities contained in the pool water. Each of the filter types will continue to clean the pool water and in the process, increase the resistance to water flow over time. The pressure displayed on the filter will increase to a point where the filter media will need to be cleaned. 

Cartridge Filters have a media that consists of a cartridge element. The element is designed and made from a material called Remay that provides a large surface area in which to trap debris. Cartridge elements cannot be backwashed, to clean they must be periodically removed and hosed down. Once clean, the element is replaced and the operating pressure is once again lower. 

Sand Filters have a granular sand type media. The sand is normally 16/30grade sand but you will find different media suitable for use such as Zeolite or Glass media. A sand filter does not have a large surface area such as a cartridge filter in which to trap debris but overcomes this limitation to a degree by the ease in which it is cleaned. The image below illustrates how water flows through the sand media during filtration. A pressure increase in the filter is proportional to the debris trapped in the media. Once the pressure reaches the design maximum, the filter is Backwashed to clean the media. Backwashing is a procedure controlled by a multiport valve (MPV). The water flow is reversed for approx. 3 minutes to lift the dirt from the sand and deliver it down a waste line. This procedure cleans the media. Immediately afterwards, the MPV is used to perform a 30 second rinse. Rinsing is the procedure where the sand media is bedded back down and all the loose debris is flushed to the waste line and not back to the pool on start up. 

 

How To Choose

The first thing to consider when choosing a filter is whether it will be Cartridge or a Sand Filter.

This may be governed by personal preference but below are some differences to consider. 

Cartridge Filters – Pro’s

  • Cartridge filters operate on wider flow rates than sand filter because backwashing is not a consideration
  • Cartridge filters, if sized correctly, will only require the elements to be removed for cleaning once or twice per year.
  • Cartridge filters filter particles down to 40 microns (Sand Filters are approx. 100 to 75 microns)
  • Cartridge filters are smaller than sand filters
  • Cartridge filters operate with a lower pressure drop than sand
  • Cartridge filters do not require backwashing and therefore save water 

Sand Filter – Pro’s

  • Sand filters are easy to clean using a multi-port valve to backwash and rinse (This can be a significant advantage over cartridge filters where dirt loadings are high)
  • Sand filters are less expensive than cartridge filters

 

Once you have chosen the filter type, the size of the filter is the next consideration. The filter size is solely governed by the flow rate of the existing Pool Pump. Ensure the filters design or maximum flow rate is suitable for use with your pump. 

 

Full Sand Filter Range

 

 

Full Cartridge Filter Range

 

If you cannot find a filter listed on our website,
Contact Us Here or call (03) 9439 9214. 

 

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