Seems like every time I see a fish that I really like, I do some research and find out that they grow to be 12" or even larger. Frontosa, Iridescent Sharks, Plecos, etc. But how long does this take? I know, you are going to say that they are way too many factors, etc, but ballpark it. 1 year, 5 years, 10 years, more? I mean it would appear that 50% of the fish in any pet store require over 100 gallon tanks in the long run, and I can't imagine that very many people have tanks that size.