after being lost for a while, then moving into a pretty bad spot in my tank, i have a green bta that is coming back nicely from being called bleached (moved its rock uptop of the aquascape). i've been feeding it a turkey baster of my mush food a day. the top portion is about 5" diamter, and if it didn't bubble i'd think it was a carpet. so they CAN come back, but yes it is tough to balance food and water conditions.