If it is filled and maintaied- indefinatly. I have tanks I care for that were started in the
60s- metalframe tanks even. I have a ten gallon I got in 70 that is still fine, and has been wet and dry dozens of times. Likely the older the tank- the likely stronger the build- at least pre late 80s. Silicone would have to be seen to be judged- and that can happen to a new tank with a razor scraper and a few beers.
|