(not that shocking). My FC had been losing more than expected lately (after lots of rain, a 30% refill, lots of pollen, and 1st use). Kept bringing it to 5.0 and next morning it's 1-2. CYA 45-50, TA 75, CH 340, pH 7.6. Clear water, no visible signs of algae.
Decided to shock this morning since I hadn't shocked for at least 6 months. I had some "Zappit" from the previous non-BBB owner, so I threw 4 cups in, only got it up to 10. Decided I'd use Clorox for the rest of it, 1 gallon got it 16.5, just what I was looking for.
Can I check CYA while at high FC? (I was just wondering how much the Zappit might have raised it, since that might effect shock level needed).
Can I check CH while at high FC? (Zappit is supposed to raise it, just wondering how much).
How many hours does the FC need to stay at 16.5? Just the overnight not more than "1" drop?