The following are characteristics of Modernism: 1  Marked by a strong and intentional break with tradition. 2  Belief that the world is created in the act of perceiving it; that is, the world is what we say it is. 3  There is no such thing as absolute truth.  No connection with history or institutions.
Pool filter cartridges can run for about 2,000 hours for a filter pump. Usually filter cartridges have to be replaced once every 1 or 2 years. The life of the filter will be less if you enter the pool with suntan lotion, deodorants, mousse, styling gels, and other damaging chemicals.
The flip side to this is that after enough time the sand will no longer be able to filter the water well enough. From a manufacturer standpoint it is recommended that you change the sand in your filter every 3-4 years. This will maximize the effectiveness of the filter and help you to maintain clean and clear water.