Taking control of my pool.

Hello!
I am new here and have found endless information on poolsolutions.com that has been so appreciated and helpful. I do have a few questions but most important, my next step and when.

2012: 28,000 gal lagoon vinyl pool with spillover spa. SWCG with DE filter and variable speed pump. Water temp approx 53, air temp 60 and overcast

Opened the pool 3 days ago.
-dumped 5lbs of Trichloro-s-triainetrione BEFORE coming across poolsolutions.com
-tested (with drops) yesterday and today. Small decrease in already low chlorine level, possibly due to sunny day yesterday.
Today's results:
CL: <.5ppm
pH: <6.8 (but not far off)
Alk: 100ppm
CYA: approx. 35ppm
Hardness: difficult to say, turned purple initially, not blue which I believe may be due to copper in the water?? I got the color to change to a little more blue at about 400ppm (did a strip test for the heck of it and it read approx. 250ppm)

After research and yesterday's test, I decided to drop the alkalinity a little via the aeration method since I can accomplish that with my spillover spa. I have been running it non-stop and Alk dropped 10ppm. If I am understanding this process correctly, I am hoping this will increase the pH to about 7.2. No change yet in pH from yesterday to today.

The pool is looking pretty clear today after vacuuming and the 5lbs of shock initially added.

Deciding what (and when) to do next.
-add a small amount of Borax to increase the pH
-wait to see if aeration will increase the pH
or
-bring up my CYA level before adding chlorine (since the salt is useless at this water level) We have had trouble keeping CYA level up in the past. I added a ton in the fall just to get it to reasonable levels, not sure if maybe the spa is interfering with this.
or
-wait until tonight to add bleach to the pool and how much?
or
-some or none of the above.

I am working on a plan to come up with my own target numbers best for my pool and system. I am sick of handing money over to the pool store and purchasing pH up, pH down, fancy baking soda and fancy borax, only to struggle and come back to buy more. Last year, I bought their algaecide, they know I have a spillover spa and they forgot to give me the non foaming algaecide...it made a mess in the spa and when I went back they sold me a $20 bottle of antifoam which I should have never needed. I am pretty sure (now) that I didn't really need the algaecide to begin with...

I am taking MY pool back! (but need help) please and thank you!

-Alisa