Hello all, I just bought a 75 g rimless tank and it is in very good condition for the exception of water stains where the old water used to rest at the top of the tank, i have scraped it,I have used vinegar a couple of times, even left it rest with vinegar for hours and still the stains won't go away. Is there any solution that I can use for this, the tank is clear as water but those stains are really bothering me lol. Thanks for any help