Hi Leah,
I've never tried it in a tank, I'm not sure how it gets on in warm water. It will grew fully submersed (and often does naturally), but it won't flower. Give it a go and see what happens, my suspicion would be that it will grow quite leggy.
I've got Ceratophyllum and Myriophyllum aquaticum (M. "brasiliense") from a pond in one tank, Ceratophyllum grows in exactly the same manner in the tank as it did in the pond, but you wouldn't believe the Myriophyllum is the same plant.
My suspicion is that Hemianthus callitrichoides ("callitrichoides" - the Callitriche like Hemianthus) gives a much better effect.
cheers Darrel