I have a Pentair sand filter that is going on its 5th year of use. Some facts and I welcome any comments:
1 - I have never changed the sand.
2 - I backwash once per year.
3 - I have pollen and dust on the bottom of the pool EVERY day and am starting to think it might be the filter.
4 - I will backwash for 3 minutes and follow the manual.
5 - Manual also recommends a Chemical Cleaning. Is this necessary and what to do you recommend I use?