If you aren't losing any overnight, then it would seem that your culprit is UV light. Are you sure your CYA level is what you think it is? When you measure, fill the tube to the first line. Look away, and then glance back and see if you can see the dot. Only glance. Do not stare at the tube and furiously look for the dot otherwise you will see it every time. Repeat and fill to the next line and so on and so forth only glancing each time until you can't see the dot at first glance.
I know you said your chlorine was fresh and 10% but didn't you measure enough last night to get to 9ppm and when you tested you were only at 7ppm? Either chlorine is weaker than you think, measurements are off, or the volume or your pool is larger than you think.
For pH, you have 2 things working against you. Your total alkalinity of 110 puts upward pressure on your pH as does your fountain. I understand the fountain cools the water, so we'll have to just deal with that. But your total alkalinity can be reduced to make your additions of acid less frequent. As I said before, lower your pH to 7.2 and then let it drift up to around 8 and repeat. Each time you lower the pH you will also lower the total alkalinity. Eventually, you will get to the point where total alkalinity and pH find a happy medium and settle down (or at least the rise in pH will occur more slowly).