i just feed mine the small sinking pellets as well and thats pretty much all they get, my suris were actually outgoing and not shy at all from the moment i put them in my tank, they immediately started sifting around and exploring, the "suris" i got from petco (i think are most likely altifrons) are a bit more shy but still not bad just back up a little when i first come to the tank and then come forward begging for food...some fish are just more outgoing than others though, you could try spending more time by the tank standing really close to it so they get more used to you, especially when feeding, also like stated its not really good to have him only eating bloodworm i wouldnt even feed bloodworm everyday (maybe only like 2x a week at most) just feed the pellets and once he is hungry enough and sees the other geos eating the pellets he will go for them, make sure they are small enough too, geos need a very small pellet size proportional to their bodies, they cant eat as big of a pellet as a bruiser cichlid of the same size could