I Got a new pump and sand filter to replace the old (Hayward Proseries, Zeobrite in place of sand). The filter works, the water has been clear (when I remember to keep adding chlorine). My pressure gauge read 17 PSI when it started to operate and it returns to 17PSI post backwashing during each of the few times that I did that. I have two observations that force the question that is the title of this thread:
1. Post-backwash there is noticeable accumulation of sand in the pool (but not huge amounts). Once that is vacuumed up, there seems to be no more until I backwash again.
2. My PSI is DROPPING rather than increasing. Last time I went to backwash the PSI was down to 10. After backwash it was back at 17. I ran the pump for two days straight to clear up an algae bloom and the pressure was down to 10 again.
Was my sand filter installed improperly, or is it normal to see some sand in the pool after backwash? I am guessing that the pressure drop is from channeling which I don't think a new filter should be doing.
I will probably call the installer, hoping they will take care of it but I want to know more about it to force the issue in case they hem and haw about it.