[We've been able to keep the fish alive, but for the life of me I CANNOT keep live vegetation alive in this tank. Even with the special gro-lite! Aaargh!!]

Alert! Alert! Novice giving advice here.....My son has just given me some Dupla Root Fertiliser (resembles large marbles made of clay type substance - though it isn't clay) and some drops of liquid fertiliser (only need to put in 1 drop/day). The balls are pushed into the gravel near the plant roots and apparently disperse gradually. The drops are put in daily because carbon filters draw it out of the water eventually. I have only just put this stuff in my aquarium so it is experimental for me, but my son has used it for more than a year and his plants seem to thrive.

Have to report that the newly introduced 'girl' fish have not died and it's 24 hours since I introduced them. The boys look happy. Must be doing something right!