Hi Marvin, try approaching the tank from one side and move slowly towards the tank. If the fish move away stop. Stay to the side of the tank to feed etc. The idea is to give the fish a safe spot. Having only three is hurting you a bit as the fish find security in group, generally at least six. Also be sure to not be walking thru areas of light or be silhouetted as you will appear black to the fish.
Pat