Some thing is damaging silicon

[waltee1000]

What's eating my silicon? This has happened within the last few days and is only on the side that has algae growing. I have only tangs and a blue jaw trigger that's has that size bite. No invertebrates at all. I have 2 exact same tanks with same water going through the same sump. So it's not something in the water that causing it either as it would show up on the other tank as well. I don't use a an algae scrubber or any other tool on those side panels. I have also uploaded the adjacent pannel Pic that shows clean glass with no missing silicon. This is a fish only system. Both tanks are new just 8 months old.

 

[chip shop]

Believe it or not I had same problem years ago and found bristle worms were the problem

 

[waltee1000]

Believe it or not I had same problem years ago and found bristle worms were the problem

I have hyposalanity 1.009 zero invertebrates. It's not a reef. All rocks were dry or diy made.

 

[waltee1000]

Well seems like the big atlantic blue tang. It's 6 to 7 inches as big as a pig and very aggressive. I caught him nipping on the edge.