I just changed the filter sand in my 25" filter with 300lbs of new pool filter sand. I back washed for about 5 or 6 mins and the water was nice and clear in the sight glass. I then rinsed for about 2 mins. So I then turned the pump off then to filter and turned the pump back on. I was expecting the pressure to be in the neighborhood of 12 PSI but it was 20 PSI. I changed the gauge when I changed the sand because the other one didn't work so I don't think it is the gauge. My question is is that to high or is that just where mine is going to be with clean sand?