I would presume it started from a 5 gal size like the first photo, from Exotica. The Brazilian Shark on here was who sold it to me this size. It is flushing a huge growth again just after adding more Dr Earth. I trimmed it back quite heavily this year and it flushed a ton after the last trim.
I have been fiddling with using Mykos. I’ve done a few not so laboratory style tests, but tried adding it in small, medium, large doses compared against the same plant in the same medium without it. It is most effective when re-potting to a larger size and directly applied to the roots.
The seedlings or plants growth is better with mykos (adds more leaves quicker), and when repotting I see substantially more fresh white roots on those treated with it. Maybe it’s just fluke, but it certainly seems to be consistent across tests, and per amount added.