I have to clean the mesh filter on our mira shower every few weeks as it is causing the shower flow to become very weak. Is it ok to do away with this filter altogether & just have a washer there? I f not what is likely to be causing this build up of sediment ? Do i need my hot water cylinder flushed & cleaned. The shower is on a gravity fed system, it is only the filter to the hot water feed that is getting blocked up, the cold is fine.