Naysen,
Your plants look absolutely stunning (especially Photo #7)!!!
The efforts you are putting into this is simply amazing. Now, you will be able to eliminate temps as a variable.
My money is still on fertilization - - (or the Worm Castings). Hope I am wrong and the aquarium heaters do the trick.
Funny, but I was sitting outside today (hit 74 degrees at 2:00pm in San Jose) thinking how I could install an aquarium heater in one outdoor EarthTainer, as I have a Rosella Purple and Iditarod Red which are in pots - but are over 14 inches tall. They need to go out - but I want to engineer a system which will give them some thermal protection over the next 6 weeks until warmer weather arrives.
My weekly update on the Inntainers will follow in an hour or so - running behind today due sitting outside in the warm sunshine.
Raybo