How long have you had the kelberi? With these an most it takes some time to realise you as a food source. But don't fret they get better
X2 overtime they will associate you with food and follow you around/come to the surface when they see you.
Adding more drift wood, rocks, plants, etc will give the bass more reason to hide. More hiding spaces a fish has, the more it will hide.
IMO, just spend more time with your bass so that they can get use to you and not be sacred of you. Add some silver dollars or some tin foil bars to the mix.
Sent from my iPhone using MonsterAquariaNetwork app