Got my test kit and took my first readings. First a little background information. We will be doing SWG, but during the break-in period, the PB's service guy had me do a shock and added 4 tablets 3 days ago and then I'm to do another shock after a week. He added sequestrant, CYA, and some dry acid. I've added some additional dry acid based on pH readings from the test strips he gave me. Here are the readings from the TF-100:
FC - 0.5 (I would say the reading was probably a little higher than 0.5, but not 1.0)
CC - 0.0
pH - 7.5
TA - 100
CH - 110
CYA - 20
It looks to me like my chlorine levels are dropping very quickly, which makes sense since I have very little CYA and full sun all day long. I didn't understand his double shock approach, but now I think I do. He doesn't want to waste his time teaching me how to control the chemistry using chlorine when I'm going to be switching to the SWG anyway. He probably wasn't sure how long the chlorine from the shock would last, but the assumption is that any problems that develop after the chlorine is gone will be killed by the second shock. I'm not comfortable with this approach because I can practically guarantee that the PB won't be out to start up the SWG for 3 weeks. I'd rather actually be in control of the chlorine level.
I plan to add bleach tomorrow, but my question is whether the second shock makes any sense or does my assumption sound correct? Any guidance on how much bleach to add would be appreciated. The pool is about 27,000 gallons. I don't mind adding slowly and checking it as I go, but I'm not sure whether to start with a quart or 3 gallons.
Also, based on these readings, is there any preference for dry acid or MA? I have some of both on hand, but was planning to use MA long term.