you shouldnt have too much of a problem getting your blenny to eat frozen. mine took mysis shrimp a week or so after being in the tank. i think he picked some up by accident picking at pods, same thing with bloodworms. now when its feeding time he swims almost all the way up to the top and "treads water" until some food reaches him. hes a character. he also loves live blackworms and live brine shrimp.