Wow! What a great reply and tons of information. I do only use a handful of chemicals: NaClO, baking soda, HCL, and calcium, but I have only been employed here for about 7 months. Some time before me, there were several different people adding chemicals to the pool, and they ended up with a high CL level that was bleaching out the indicator, so they though it was 0 CL and continued to add CL. One of their water samples tested at 55ppm CL! So they added Chlor-out, and I am not sure what else...
The pool water temperature is maintained at 86-88 for the senior water aerobics classes that meet here 3 mornings/week. Most think that 86 is too cold. We also have 2 hour swim team practices every night, so I am sure that there is tons of sweating. Do you think that reducing the water temp to the low 80's would help improve the water quality much?
Thanks again for all of your advice! I will do what I can to implement the changes you recommend.