I have used fibre glass on a few tanks now to seal cracks in the glass. I reckon its a handy way of repairing tanks, though if the crack is on the viewing pane i wouldnt recommend it for asthetic reasons. Anybody else had similiar experience
It depends on where is the crack. If you can use a scrape panel of glass with silicone to fix the crack, you can use fiber glass too. However, for certain part of the tank, I would definitely not do either of these technique due to structural issue, not just astetics.