7 year old condo construction and exterior corner wall, so I realized I’m not likely to run into any problems, especially since I can’t imagine doing more than 50g at this point. This probably won’t happen for another month anyway, so I’ve got plenty of time to research tanks and stands before switching it up. @Tamberav scared the crap out of me because just yesterday my son was banging on the tank with a metal spoon my mom gave him (bad grandma!!!). He’s rarely unsupervised but it’s the things he does quickly when I’m not expecting it that worry me most.One gallon of saltwater is around 8 to 9 pounds. I wouldn't do anything above 100 gallons on my second floor just because of the water damage in case of a leak, but I guess It would depend on how old the house is and good the construction was.