Hello; It is a hobby not an obsession, at least for me. I have had the interest wax and wane over the decades. Work and other things have had an impact. I have been down to one small tank a few times and numerous tanks at other times. Now that I have made it to retirement and have a place of my own, I too have only three tanks running.
I have four empty tanks in the basement with some vague plan to set them up. I can do whatever I want and do not get around to it. As I can do anything I want, three tanks must be it right now. Having a large number of tanks can be a chore but also rewarding. Having one or a few tanks can be easier on the wallet and also rewarding.
It's a hobby, do it any way you like, except for those living in someone else's place. Renters, those living with mom and dad and those who are married will likely have to cut a deal.