A scooter Blenny has basically the same dietary needs as a mandarin. Basically, all day long they eat live copepods. An immature 55 gallon tank with 90 or so lbs of live rock will not sustain it. You could buy some live copepods on the Internet to try and supplement your current population, although this is really a short-term fix.
As mentioned scooters do not eat algae (this is not a lawnmower blenny), and in the future it would be a good diea for you to reserach the needs of a fish before adding it to your tank....but we do all make mistakes, and I have made my share as well.
While it is a good sign that you have a few hundred copepods, you should be awrae that a scooter blenny will go through that number of copepods in no time at all. (figures as: it constantly eats, maybe "picks" on the rocks every 10 seconds, which equates to 6 copepods a minute, 360 an hour, and thus 3600 copepods during a 10 hour light cycle).
So basically, without a large tank with tons of LR, and/or a fuge for the pods to reproduce in without predation, your chances of keeping the scooter are VERY slim. You might try getting it to eat some form of frozen food, but I do not think your chances are very good (under 5% from what I have red).
Sorry it is not better news.
Stewart
