Hi..

water lettuce,

Well, have kept offshots indoors for three winters now.
Never had any problem with them in open unheated tanks and
in a small half-open tropical tank without filter.

In winter its small leafs (as big as coins) look like
"hairy" European frog-bit. At the moment mine beside the
Souterrain window start growing and raising its leafs in
its typical manner.

hyacinth,

Well had no good experience with them in the house. They
didn't like condensation, got mould..

No tropicals but good in summer ponds:

Egeria densa,
Parrot feather,
Water cress,
Ludwigia
Rotala rotundifolia

--
cu
Marco