These are my plants:
-- Echinodorus tennellus (Narrow Leaf Chain Sword)
-- Sagittaria subulata (Dwarf Sagittaria)
-- Anubias barteri v. Nana (Anubias Nana)
-- Hygrophila difformis (Wisteria)
-- Cryptocoryne wendtii
-- Cryptocoryne lutea
-- Ceratopteris thalictroides (Water Sprite)
Since I bought the Wisteria, it has just wasted away. The Water Sprite, too, though it puts up nice new growth... which then just waste away.
My other plants are doing okay, so do the Wisteria and Water Sprite have special requirements?
(Actually, the Sagittaria hasn't done much at all, and the Chain Sword hasn't done well except for putting out chains of new plants. So it's not like the rest are doing great, but the Sprite and Wisteria stand out as the worst.)