I think you have it figured.
A couple thoughts...
1) The pH tester tops out at 8.2, so you may have been much higher than you thought, hence the big appetite for acid. The jump from 9 to 8 is ten times the jump from 8 to 7, so I don't think you've done anything wrong. You probably just didn't understand the logarithmic scale nor the limits of the pH tester.
2) You have high TA, so rising pH is going to be an ongoing battle until TA gets down around 70, give or take. Each time you lower pH, you'll lower TA a little bit.
3) Your CYA is pretty high. It's okay of you have a SWG, otherwise, it could give your grief if you ever develop algae.
4) With CYA of 80, you need to maintain a much higher FC than you have. [FC/CYA]Chart[/FC/CYA]
Advice: Keep working on adjusting the pH down. If you still have some dry acid (That's another name for Sodium Bisulfate ) left, use it up, and then don't buy anymore and switch to Muriatic Acid. Dry acid has sulfur in it. I don't know what conditions it needs to make it smell, but I sure don't want to find out. So finish it off and be done with it. Otherwise it's just more hazmat waste to hold onto until the next collection. Raise the FC to the appropriate level in that chart
