The simple answer would be to maintain the system.
However, to further explain why this is necessary, we need to first address what happens to the cartridges overtime. Many filters work by using pores or media to trap the bacteria and contaminants in your water. Overtime, these contaminants build up in the cartridge and make it difficult for water to flow through the cartridge. The water that manages to get through is unlikely to be filtered effectively.
Some filter cartridges (such as pleated sediment cartridges) can be re-used by removing the cartridge from the housing and washing it with clean water. Pleated cartridges should only be re-used 3-4 times before they will need to be replaced with a new cartridge.
In the image below, the filter cartridge has become brown and is visibly dirty. This was after only 6 months of filtration of scheme (mains) water in Western Australia. Indicators for replacement included the presence of chlorine taste in the water. However, the customer did not think the cartridge would be this bad.
Sometimes it may be obvious when as filter needs replacing due to the return of taste and odour in your water, although, it is not always this noticeable. Because of this, we recommend replacing cartridges every 6-12 months or when the taste changes or odour returns.
If you are unsure on when your filter needs replacing, give us a call on 1300 081 169.