ewkearns: the pool was empty for at least a two weeks before being filled so I wouldn't leave it empty long.
singingpond: Yeah. The pool builder is a bit hard to find right now. He doesn't understand the chemistry AT ALL and his guy that does is baffled by this. I've called several pool professionals and none of them understand. One doesn't do SWG at all and one that did had no idea that aeration raises pH so I wasn't trusting these people to help. I'm reticent to start manually chlorinating. I wonder if it's the filter running more often because of the termite swarms and bugs that occasionally end up in there, though the SWG is not running any longer because I drop the percentage.
chem geek: I actually never added acid when I didn't check the pH and TA after. The lowest I ever got it before a couple days ago was 50, when I added the borates, the pH was already crazy before that and the lowest I'd gotten it before that was 60, which isn't that low for SWG. A couple nights ago I got it to 20 but I immediately raised it up with sodium carbonate. Originally the Hayward Sense and Dispense used
CO2 but apparently they use an acid tank now. I'm not sure why but I'd prefer the
CO2 if it's possible to get though they may not support it. I want Hayward equipment because it's all controlled by the OmniLogic which I love.
onBalance: Thank you for weighing in. I can answer some of that:
1. The CH of the tap water tested at 175. The TA, as you mentioned, is 140, and the pH is higher than 8.2, though probably too much higher.
2. I don't know what the temp was like the day of plaster but it was probably around 70 to 80.
3. The salt was added within 24 hours of filling the pool.
4. I don't know but there was an unopened bottle of muriatic acid left behind so I'm guessing they used some beforehand. I will find out when I can get the pool builder to call me back. I'm having some difficulties there. New Orleans is an interesting place, to put it kindly.