I just recently picked up a used 25 gallon glass tank that was completely caked with who knows what... i'm guessing calcium buildup, mineral deposits, etc. Basically there's white gunk on the outside of the tank that's caked on the surface in some areas that I've been trying to clean off with very limited success. I've tried just a good scrub pad, scrub pad with windex, and just tried CLR but nothing seems to be working. Anyone have any suggestions to clean this white crud off??
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