Wow that linked article was intense. Thank you for that!

This is exactly what I do at work in the BioPharma lab growing cell cultures. Controlling pH, DO, temperature.
We agitate, sparge with CO2 to bring pH lower and add base to raise pH.
We sparge with Air and then O2 if it gets too low controlling DO.
We have complex nutrient and glucose feeding cycles.
I guess I already understand and know what to do. I will try to make it as deep as i can and leave a ramp to get out.

The part I didn't see coming was the fish making the water acidic by breathing. My cells do it in the lab so I get it...
I should plan to add a bit of lime occasionally.

So after all of this fine advice it seems like I really need to add a bubbler. I could run it for free during the daylight hours as I am off the power grid and use solar. Please recommend the best one for my application.

If I was using my own fish food what should I grow? Are there any plants they would consume whole? (Bluegills)

THANK YOU!