Lawnmower Blenny ill

[Force4000]

I picked up a lawnmower blenny about 3 weeks ago for my BC14 gal. He seemed to be doing great until last night when i noticed he was seemed to be breathing heavy and not moving. I waited till today to see if he got better but it doesnt seem that way. He is now sitting at the bottom of the tank not moving. I can seem him rapidly breathing and it looks like his gills are puffed out. He was floating at the bot on his side earlier but now hes sitting upright again.

I checked my water levels and everything is perfect. nitrates, salinity etc.

I also have a:
Clownfish
Peppermint shrimp
black baby urchin
Hammer coral, frogspawn, bunch of other corals

Everything else in the tank is doing great so I am not to sure. Any ideas would be helpful. Theres a ton of algae for him to eat which has been up til yesterday. I havnt seem him eat since then.

 

[Force4000]

I removed the blue filterpad in the back of my Biocube and cleaned it yesterday. It was full of gunk and as i pulled it out a lot of gunk floated into the tank. Is it possible he ate some of this stuff and got sick from it?