It usually varies depending on the filter. Generally though, in order to check whether your 30 square feet (D.E. Replacement Module) filter needs to be replaced, you first need to gauge the pressure of the water coming into the filter when the pool water is still clean. After a while, when you think that your pool in getting dirty, gauge the filter pressure again. If it has risen to about 10 psi, then its time to clean your filter cartridge.
There are two things that may happen when filter cartridges are clogged and dirty:
- the pressure on the filter rises
- the flow rate of the swimming pool's water circulation system decreases
When this happens, the efficiency of your pool's filtering system is compromised. Be sure to always check and clean your 30 square feet (D.E. Replacement Module) in order to avoid this.