Sand Filter getting clogged?

I have a 24' AG with a 1.5Hp pump + Hayward sand filter that I run 8hrs/day, normally. The backwashed (ie: clean) pressure is normally around 14lbs. When I use my bug vacuum after a fair amt. of debris get on the bottom, the pressure in the return drops greatly. The pressure reading usually peaks at 18-20lbs. The only way I have been able to get the return jet pressure back up is by backwashing. However, the water in the sight glass doesn't get all that visually dirty (then clean) during this process. I see some specks in the glass, and usually backwash for 1-2 minutes. After a rinse, the return jet pressure is back to max, and the pressure on the dial is back to around 14lbs. My water is crystal clear.

Q: is this normal to have to backwash every time I vacuum when the pressure is only up 5-6 lbs? I've heard bad things about random backwashing, but this is the only way to get the return pressure back to normal. Thx.

Normal. Not sure what could be bad about backwashing other than having to replace water.

Nothing about this sounds abnormal other than the sight glass looking relatively clean throughout the backwash process.
I wonder if it's just not picking up enough of the flow to show what's in hte pipes - does your backwash line go into an underground pipe? Mine is only 3 feet long and empties onto a large flagstone before it spills onto the lawn and the water that comes out upon backwashing is relatively filthy (grey) looking and compares to what I see in the sightglass 1 for 1.