That's a beautiful tank manu8! I still have the first (and only) amazon sword I ever bought. It's about 4yrs old. It started as a pethetic Petco/Petsmart plastic tube plant purchase. I made the mistake of planting it in a 10g with floramax substrate. It took forever to take off, but once it did, I had to rehome it. I'll never forget when I pulled it from my 10g, the root system completely took over the footprint of that 10g! I fluffed the whole bottom pulling it out.
It started out as this. The center/right plant:
and grew to this in about a year:
I run my tanks at 72-76F, but they can run hotter in the summer. I tried API root tabs once and used Metricide for CO2, seachem comprehensive and trace, but I'm sporadic with those.