I also have a GTBA and it is the same but mine has found a spot it likes nice and high and the flow is a bit less up there. I did try and feed mysis it didn't take it now it fends for its self it must be getting food as it is growing and pretty fast too. there is nothing missing. I stopped feeding because it had found a spot and after trying to get it to eat it moved and I do not want it to try and cling to a power head. It has found a spot and has stayed there I did see it eat a bristle worm the other night that was swimming in the water column I do have a wrasse that may have kicked it up.

Bill