OK, here is where I am today. I added 2 cups of muriatic acid yesterday. PH started at 8.0 and was at 7.5 after a while. TA dropped to 80 from 90. I also added another 3/4 pound of stabilizer, so I will have to give that a while before testing. I added four 96 ounce jugs of 6% bleach last night to shock, which actually took FC to 16.5 ppm. I checked again this morning and FC was 16, so I only lost .5 ppm overnight, which is a first. Do you think that is partially due to dropping the PH, making the bleach more effective? However, my TA was up to 100ppm this morning. So it started at 90 yesterday BEFORE the mur. acid and dropped to 80 yesterday after the acid and was 100 this morning. The PH had also drifted a bit more as well, and was around 7.3 this morning. I believe PH readings are not that accurate with shock levels??

Also, there was much less algae in the pool this morning than normal. I vacuumed yesterday morning, and brushed the pool down in the evening. I rebrushed the entire pool again this morning and will check chlorine levels again in a few more hours.

I feel like my CYA is soon to be near the 30+ mark. I know it is >0, but ,<30, as I can see the water is cloudier than plain pool water when it is in the tester, so I think that will be in line soon.

Dave, you recommend adding Polyquat, so can you tell me how much I should add for 11,200 gallon vinyl pool? And, do I need to continually add polyquat after this initial dose for maintenance sake, or just one time? I really want to take all measures to get this under control before I leave on Saturday for the week. My friend will be able to vac. and brush and add bleach, but I really don't want him messing with any other chems while I am away. No telling what I could come home to though.

Anyway, let me know what you think so far.

Thanks for all the help from everyone, btw!

John