So I definitely should've posted this question in early October when the pool company came to close our pool since I think I might be forgetting things. Bear with me, please!
We used a different company to close our pool than we did in the spring to open it (this has been our first year in this house, first year with a pool), mainly because we bought a mesh safety cover and this company gave us the best deal and came recommended by a family member. Prior to the (very late, they say they were very backed up with orders) actual closing, I shocked the pool using the SLAM method here on the website. I'd been doing BBB for past couple months with excellent results. Since it was overcast and chilly already, my chlorine levels weren't going down much after SLAMing, even after 2 weeks (I'd have waited but they kept telling me they'd be here "any day now") were still around 10. I tested 2 days prior to them coming and got the 10 reading, so maybe a touch lower but was still not sunny and based on how slowly it was going down before that, surely couldn't have dropped much more. I had been testing with my TF100 and all levels were great at last full test, 2 weeks prior (since then I had only been testing pH and chlorine). The last results I have still in my notes were pre-SLAM, with a pH of 7.6, TA 50 and CYA 45. Basically what I'd had for the past couple months.
I remember I lowered the pH to 7.2 before SLAMing. Also remember that I passed my overnight loss test the first night, and that after SLAMing, the pool dropped chlorine extremely slowly-- a week later was still at 12 and that was with a good amount of leaves in it. We scrubbed and raked again a few more times as we waited for the pool company to get here, ugh. Was annoying, all that waiting.
Anyway, here's my question. Husband was home when they came to install the cover and close the pool and he told me they came and told him our TA was low and they needed to add 15lbs of 'alkalinity up' to bring it to proper levels for winterizing. Since my TA and pH had been pretty consistent all summer, I can't imagine why they'd need to do this. Husband ok'd it and they used some soda ash that was in our garage from the previous owners. Is 15 lbs as much as it sounds like it is? Could my TA have dropped a lot after my muriatic acid dose to get it to pH7.2? Was less than half a gallon of acid, seems like no big deal.
Basically I'm wondering if I should go take the corner of the cover off and test my water. Can't imagine I could do anything about it now regardless. I was told not to worry about checking it until Thanksgiving, and mostly just to be sure my water level isn't getting too close to the skimmer.
Sorry about the wordiness, I can't summarize worth a you-know-what. Thanks in advance,
18Kgallon IG vinyl liner
Hayward DE 4820 filter
Baltimore MD in full sun til 5pm (in summertime)
plenty of leafy trees around