Ok, so I finally bit the bullet and tore down my DE filter (Nautilus NS-60). It was running about 30 PSI when I bought the house. I backwashed a couple weeks ago and have been running in the mid 20's since. I neglected to take any pictures during the teardown, but I have a few of the aftermath. All I can say is _wow_ that was nasty.
It's the first time I've ever been in a DE filter, but I don't think there should be softball sized chunks in there. It was basically packed tight between the grids. Found a tear in one of the grids, but the previous homeowner left me a couple spares in the shed.
In the process I managed to let the filter drain back into the pool and cloud the water. But after getting it back together and running the filter overnight, wow.
That's the main drain at 7 feet.
Now the filter is running at about 9 PSI

Didn't realize that was possible...
Now I'm having issues with the Kreepy Kraully. Mine plugs in inside the skimmer. With it connected my pressure drops off to nothing and the pump is starving (cavitating) I added an "automatic pressure regulating valve". The pump seems ok now, and running about 1-1/2 PSI less than without the Kraully. But I'wondering what I do about the filter basket? the Kraully has a leaf catcher, but the water that gets in through the regulating valve has no strainer or such. so this morning I pulled a couple handfuls of junk out of my pump filter basket. So I think there's some other way to hook this up?
One more thing. Give me a second opinion on these readings
I'm thinking Chlorine between 1.5 and 3.0, but Ph... what 8.0?
Thanks