Thanks for deleting the other post and replying to this one. I have a cheap test kit right now but will likely order a better one soon. The computer on the pool seems to be able to detect salinity and other things but I don't know how to use it yet (and it came without the manual). The tester goes bright yellow well off the scale after adding.

I will replace the gauge on Monday I think. I have been back washing every few hours as the water is so nasty I figure it can't hurt to keep the filter clean. I wonder if it is safe to run all night with the water so dirty? I don't want to burn out my pumps or cause a leak.

The average depth of my pool appears to be more like 5-6 feet based on the soundings with the pole. The shallow end is close to three feet and the deep end is around ten with some moderate sloping. That should make it more like 30K based on your formula.

Something disturbing today. While scrubbing for algae some silver sided duct tape came up as well.... I sure hope they were not using it to patch a leak in the bottom!

PH reading is up and down from 6.4 to 7.6. Appears to jump when I add more CL.