. . . membership upgraded.

The only immediate problem I see is with your pH, which is too high. Depending on how you're testing, it may be WAY too high, since with many kits a reading of 8.0, doesn't mean it's 8.0, it means it's 8.0 OR HIGHER.

So, add some acid till it's below 8.0, at least a little => see http://pool9.net/ma/

Scaling sides that can be cleaned with a pressure washer AND you have low CH? Sounds like sand algae residue => http://pool9.net/algae-sand

Good luck!