Hi Dan, and welcome to the forum! I'll try and answer a few of your questions.

Regarding why you haven't had algae in the past? Don't know for sure but I guess it was because you shocked after the "bac pac depletion," (I have no idea what bac pac is.) How did you shock?

You do have enough cya in there. 45 is a good level. Just maintain cl levels between 3-6 and your shock level when needed will be 15.

To add calcium, you can use cal-hypo for your source of chlorine until you get the calcium hardness reading between 200-400. Then, you'll want to switch to bleach.

Don't need the ozonator. I think you could just remove it altogether since, if you follow our methods here, you'll most likely never use it again, but that is just my opinion.

Glad you are enjoying the forum and thanks for the kind words. We enjoy helping people learn to manage their pools. Repost if you have other questions and good job doing your "homework" and reading through the info on this forum.