Hi there!
Had a few situations lately that left the spa unattended to for some extended periods of time, and I had one with probably a week, and another with probably two weeks, of time with the chlorine to zero. I'm trying to make sure I am safe for use going forward...
I added up to 10ppm chlorine, let it circulate a few hours, then drained and refilled, cleaned out the filters, some scum around the water line, etc. Refilled and shocked to 10ppm chlorine, and it was already down to 1.8 ppm the next day, and I've been adding chlorine to 6ppm daily since, and the chlorine demand is definitely leveling off, around 2.something ppm per day. I used it last night and so far so good, I hope.
Will this be ok? How likely are biofilm problems? If there is some biofilm here and there is that a major problem as long as FC levels are ok? Or is using it the next few days asking for trouble?
Thank you!