Looks like cyano
alage. I don't think a lawmower blenny will eat that stuff though. there are snails that do though, check out ReefCleaners.org | Clean Up Crews and Macro Algae
they have some nifty clean up crew.
I would vacuum as much of that red up as possible during your water changes though that will help to get rid of it. Are you using ro
water and how often do you do water changes? What is your feeding schedule and what do you feed? And finally what type of water circulation do you have and the tank size?