Nice glassfish by the way! Bit of a glassfish fan myself. Very entertaining fish... and again, often misunderstood to be brackish water fishes when in fact they prefer the usual neutral, moderately hard water of other Southeast Asian species.
As for BBGs, the story is complex; while Naomi is certainly correct that they are found in freshwater habitats as much as brackish water ones, they do tend to be easier to maintain in brackish water aquaria. Frank Schaefer puts this down to simply being able to keep them constantly supplied with brine shrimp! In any even, my feeling is most specimens die because of lack of food. I have two in a freshwater planted tank, and they hardly seem to eat anything. They have lived there for at least a year though, and my assumption is that they eat baby cherry shrimps (there are dozens of adult cherry shrimps in there).
Cheers, Neale