This may be a ridiculous question but I was wondering if anyone has kept fabric under their gravel? I am planning on getting a new tank and was thinking of putting some type of fabric on the bottom of the tank before I add gravel to give it some cushion against the glass. I was moving stuff around in my other tanks with some semi-heavy decorations and the scratching noise the sand and gravel made against the bottom gave me a terrible feeling. Is the glass damage so minimal I shouldn't worry about it? Would keeping fabric down there have bad effects on water chemistry or bacteria? What type of fabric should I be considering? (I have a lot of extra felt) Thank you in advance for entertaining my silly notions.