I'm always paranoid scrapping coralline around my glass tank's corners. Any tips? Or should I not be too worried? FWIW: My tank (Aquarium Obsessed) has a good deal of excess silicone (I don't know what what to call this ... just silicone that extends beyond the glass, forming a thing layer). I'm always paranoid when I scrape this a bit; it's hard to avoid removing some of the silicone.