red brown is good it meen that their photosynthetic cells are working they probably have a green tint where the bubble forms most of the time they are bleeched out and almost all there photo cells dead or some thing to that effect. If the BTA has regained its brownish color you are doing things right. My nems get fed every second day other than the carpet Nem as it may start hunting for other food like fish. My carpet nem gets fed every day neough to keep it happy and the clowns are now bringing it food also. What size tank do you have you may have to move or sell 1 or 2 of the BTA's Nem's geraly don't like compition and will get rid of it. BTA splits can reside in the same tank because they are the same animal. some thing to think about this maybe causing your trouble also a kind of diffence mechanism.

Bill