Herbivores fish

[h2pvnus]

Need some recommend on herbivore fish that around 4" max.

 

[Marshall O]

Look into Blennies. That is about all I can think of that meets both requirements. However beware, as some are known SPS eaters, and others (i.e. Lawnmower) become quite belligerent as they mature, and can also be very difficult to feed. I had one starve in my 55 gallon tank.