To upgrade or to downgrade??

Currently I have a 55 gal upright that I'm battling a case of Dino. The tank I purchased second hand off someone and it was in decent shape and no leaks. I just had to reinforce the rims with clear vinyl tape. I noticed not too long ago that the tank was build in 1997. Now I can't help but feeling that this thing is a ticking bomb waiting to spring a leak lol. I also have another 15 gallon tank that I use as a QT/Frag tank but haven't treated anything with copper in it so it's a clean tank. My problem now is deciding to either upgrade to a 90 from Deep Blue that I've had my eyes on or downsize and make a nano sps reef out of the 15 gallon and sell my flame angel and foxface. Drill it and plumb it to the sump I already have for the 55. The problem in my life right now lol

 

question, do you have young kids? The answer will help me answer the poll.

 

no wife or kids and recently single lol

 

Easy vote

 

lol.

 

Definitely upgrade