Another question regarding scraping algae and coralline

[newreefer_59]

I have an Algae (lawnmower) blenny......If I am removing the algae and coralline form my glass, is he able to get by feeding off the live rock, etc? Seems he is always chomping on the glass for his meals.....and is getting a bit of a girth...lol

Also, should I clean any coralline that builds up within the sump or should that be left.

Thanks.....