You did my dream! I have just read from the beginning this chat and I appreciate your details follow up.
I guess we're all look forward to see your tank with the fishes.
Some remarks : Are you not afraid about the plants and Petro behavior?
Airlift is a very good system, I experienced this in small tanks and I always remark that fishes seem to appreciate. My guess is that traditional pumps generate vibrations that are not good for the fishes, in addition this oxygens well the water and the energy consumption is reduced...
I would not use brass connexions for the airlifts inside the water, I think this is not good in term of risk of contaminent diffusion (even if the water volume is big here) I would use plastics.
In term of background, you probably have achieved the most realistic biotope simulation ! congratulation - The only one who I know and who did that is Julien ( Tank Ganyika), however he was limited by a front lenght of two meters...
Please continue to give design details ( heating system...) and also some nice petro pictures