So, I got my new TF-100 kit from Fedex yesterday and of course has to try it out right away.
So last night, I took a TC reading using the block and it was 0.5 (I opened the pool last weekend and just turned on the SWG yesterday morning to full power). The TC was 0 before that.
So, I decided that it would take too long for the SWG to boost the FC and I was worried about low FC as the air temp and sun were getting more intense (actually hit 90 deg in Massachusetts last weekend). So I decided to shock the pool using the pool calculator and bleach. Based on my numbers as measured by the TF-100.........
TC = 0.5
CYA = 60
TA = 140 (this seems high)
PH = 7.6
the pool calc suggested a shock FC of 18 and suggested to add (11) 96oz jugs of bleach to get from 0.5 to 18.
I wasn't sure I wanted to add that much Chlorine, so I only added (6) 96oz jugs.
I tested the chlorine in the morning (6:30am) and got........
Based on the calculator and adding only the 6 jugs, I was only expecting FC=10.5, assuming no FC loss over night. I am scratching my head to figure out how the heck FC still reads 15.5 in the morning. I'm kind of glad I didn't put the suggested (11) jugs in otherwise the FC probably would have been double. I am wondering if something went wrong either in the tests or using the calculator.
Also, this raised another question for me......what is a safe FC level for swimming (assuming CC=0)? In other words....how long after a shock should we not use the pool?