Thank you Chem Geek and Carl D. I feel better after seeing your responses. This has been a stubborn run of algae that I had been marginally keeping at bay for the last 4 weeks or so. However in the last week it really got bad so I had to hit it hard. I've added 4 gallons of 12.5% chlorine to 24k gallons in the last 4 days and brushing daily and last night finally with polyquat.

I can attest that the Polyquat must have driven my CL level down, because last night it was well over 12ppm just before I added the poly quat, and this morning it was about 6ppm. Unfortunately I was out of CL this AM so it will have to wait till I get home from work to boost it back up. I'm also hoping to not see new algae growing

My numbers this morning are:
FC ~6 (last night 12)
pH 7.8
TTA 100
CYA ~60 (Higher than I'd like, and next year I'll use tablets minimal to keep it low)
24k gallon vinyl.

Thanks