DE in Sand Filter,2spd pump

[Davenj]

I have a 500lb sand filter with a 2spd pump. Added some DE to sand filter on high speed. Do you check for 1psi increase on high or low spd. Also, my pressure never seems to go up that much 2psi after about 3 weeks of running. There is a difference in water clarity after I backwash. Normal pressure is 22psi on high and 8psi on low spd.
22k gal IG vinyl, spa
Any thoughts,
Thanks
Dave

[day1]

Your pressure may not rise much because you have such a big filter--500 LBS
WOW! Hell, mine's a 150 and it's big. I don't think it matters much about the speed, but if you see it blowing out of returns, might want to use low speed while adding DE. I wish I had a 2 spd pump...I'd never have it on high speed.