I have a glass canopy top for my 75 gallon tank. I find I have to replace the glass after a while due to the water etching makes the glass so foggy, I can't see through it. I have tried frequent cleaning, even with CLR without much success. Is there anything that can be put on the glass to minimize the damage from the etching? I do need to keep the tank covered for various reasons too. The new glass looks so nice, I would love to keep it that way, but I don't know if it is even possible. Any trick for keeping the glass looking like new? Thanks for your help!