Okay, I think it's time I update this thread...
The Mini-M has been changed drastically. This is what it looked at its peak:
Unfortunately the UG has deteriorated beyond saving. Despite my best efforts, it kept getting paler and paler. Worse yet, it didn't stay rooted in the AS (despite the roots being over 1" deep). Instead, it started lifting up as an entire sheet and floated around the tank. I tried replanting it, but it didn't look the same. UG is gorgeous plant, but I question its use long-term submerged. I've never seen anyone with a UG carpet lasting more than 6 months anywhere on the internet. Perhaps it's only meant for emersed growth.
Rather than continue with the UG, I just ripped it all up and planted HC in its place. The HC in my Mini-L is doing great and looks awesome, so I went with it in this tank as well. The planting process took over 3 hours because I planted each plantlet individually. I've had success doing this in the past and got a really nice root system this way.
Here's what the tank looked after all the UG was removed:
After the HC was planted:
It doesn't look very pretty right now, but from past experience, the HC won't take much time to fill in at all.
The livestock are doing great. There are 8 CPDs, about 20-25 CBS, and one oto in there.
More updates to come. Thanks for reading!