I have one of these guys in my 24 nano. What i typically do is drop thawed out mysis or brine shimp on to the sand bed and the scooter blenny seems to enjoy it. Since they are quite active, i recommend feeding at least twice a day. i usually turn off the pump for about 5 minutes during the feeding. This insures that the food sinks to the very bottom. Good luck with you scooter.
You need a mature tank to keep one of these succesfully. I have one and have just managed to get him from live copepods (Which cost a lot to keep seeding your tank with) onto frozen mysis.