Update - I went back to the aquarium store where I bought the tank a year ago and showed them the issue and they gave me a new tank as a replacement. Looks like my weekend will now be spent swapping tanks, which isn't my favorite thing, but better than a flood!! Thanks for all the advice. I checked my corner to corner level and it is fine too so not sure if this was maybe a defective tank? If I wanted to upgrade the brace on this one to glass, how do I do that? Just attach it to either side with clear silicone?