Chem geek,
I actually drained the spa this morning and scrubbed it out. The numbers were off the charts besides the chlorine which has been sitting at 0 unless I add instant chlorine to the water. I think the switch that controls the water allowed into the chlorine cylinder is bad. I can turn it from 0-5. It's been on 3 the last few days and chlorine is still reading at a zero. This spa is in a hotel but it's our slow season. When I checked the PH of the fill water (city water) I had a 7.8, I'm not sure if they normally run at that number. I back washed the system last week because the psi on the filter was sitting at 20 psi when it normally runs at 16 psi. I will have more information tomorrow on numbers. It seems to stay steady for about a week after draining, and sky rockets again, but that whole process takes about 2 days to complete. Filling a 2000 gallon spa with a garden hose takes time haha. Thanks for your reply!