G.balzanii, in my experience, plaster themselves to the bottom of the tank or pond, rarely going more than a couple inches above it. When my adult balzanii were outside for the summer, I quite literally never saw them, beyond an occasional flash of movement if I caught one off-guard by approaching very softly. In a tank, they were disappointing; in a pond, they're a complete waste of time, IMHO.
G.rhabdotus, on the other hand, don't get as big but they have sparkling personalities and swim all over the place, feeding even from the surface. I would have thought that G.terrapurpura would be similar? They're definitely a better choice than the sunfish you have mentioned a few times; they won't bother anybody else and don't even do more than the very occasional lip-lock with each other when you have a bunch of pairs breeding simultaneously. They are...dare I say this?...nice, non-psychopathic cichlids. Shhhh...don't tell
FINWIN
that I admitted that.
My water lilies were sold as "semi-hardy", which means that I am still supposed to overwinter them indoors...but my lowest temps will be an occasional -45F rather than +45F so not really comparable. I started with one, divided and sub-divided it several times over a number of years, even left some outside for a couple of winters with complete success...and then last summer (2024) they all failed to come back to life in the spring. I got two more for the 2025 season, both did well, lots of pads, lots of blooms, but I'm taking them in this week now that all the leaves have yellowed and died. They look just like yours, no idea what the actual variety is. It must be nice to just plant them and leave them.
The albino Channel Cat idea sounds great; they get big and they will eat smaller fish but they're definitely slow growers, they tame nicely and are active, and an albino will look great and be easily seen.
You're very lucky to have your parents on-board with your pond project. Make sure you keep them that way by having attractive and easily-visible fish in there and maintaining it nicely. Wasting your time and money on some supposedly-cool fish that gets oohs and aahs in a place like MFK means diddly squat to somebody who just wants to see colourful fish; it even gets old fast to the fish-keeper himself if he never sees the rare and exotic Sumatran Tiger-sucker Loach that he just
had to have... 