New here - love this site - sorry for the long post, but I need help please! Brand new small pool owner, just filled up the pool Sunday night and started with the BBB. First 4 nights added "pool shock" but chlorine levels would be 5 in the morning and drop to nothing after 1-2 hours of sunlight, so we've been adding extra bleach per the pool calculator. Finally did more checking and reading and realized yesterday the hth product we bought was cal-hypo, not dichlor, so we weren't getting any CYA. So yesterday (Thur) DH went to the pool store and came home with 1.75 lbs of granular CYA. The pool guy told him to add the whole thing and that would raise the level to about 100. DH asked if that was too high and he said no its only a problem if over 200. (!!) This morning I'm reading the directions on the empty container and it says to add 1 lb per 3000 gallons of water to provide initial level of 40 (and to run the pump for 24 hours).
So he and our son swam yesterday evening and son came out with a dirty swim diaper. Great. We didn't do anything last night but get out of the pool. Evidently we shouldn't check the CYA for a week, but I checked it this morning (about 14 hours after adding) to find out chlorine shock level and the CYA is over 100 - maybe 120?. I've only got enough CYA reagent left for one more test - will have to order more online. I've got the hth 6-way drop test from walmart.
So my first question is do I bother shocking the pool with a gallon of bleach, or are we going to have to drain half the pool first to get the CYA down?
After that, how long do I need to maintain the shock level? Do I need to buy the kit to test the FC drop overnight to determine when to stop shocking? How long before the high CYA becomes a problem?
pH has been good. It was high the first morning, but brought it down and its been 7.2 to 7.5 ever since.
Thanks so much - love this sight. Its overwhelming at first, but I'm finding it interesting. Just hope we can figure it all out soon!