The tropical water lilies really require warmer water to tell them that it's time to grow--never below 50F and ideally above 70F, in my experience. Once they get going they are much faster and more vigorous than their hardy siblings. Evelyn Randig has very pretty leaves and grows quite large. It is not very hardy, though. It will start to bulb when the water gets cooler, but it can be tricky to break out of dormancy again if not treated right.
Note that unlike hardy water lilies which generally grow and divide along the surface of the solid media substrate, tropicals usually grow straight up into the water, sending roots downward in all directions. An overly small pot will definitely dwarf the plant, but it will probably stress it as well.
