Hi Folks,
I might suggest trying tadpoles to graze down the algae. I've been
experimenting with a tank of U. inflata, and initially had massive algae
growth. While it did slack off after several months, one of our local
frogs deposited some eggs in the tank. It was probably a tree frog as
the only unscreened opening into the greenhouse was through a roof vent
and the tadpoles have remained small (4 cm). They are really keeping
the algae down and don't appear to be bothering the U. inflata.
Granted, they would have a finite tenure in an aquarium, but the North
American species that overwinter as tadpoles have a wide temperature
range. Please note that I have no experience with tadpoles and
Aldrovanda. Just a thought!
Jeff
(in North Carolina)