I seen you're getting a 180 how wide and how long is it. because that snapper gets 3-3 1/2 feet long and i would say it will be a thick and tall fish as well. Also a 180 is pushing it for even 1 catshark that gets 2 1/2 feet long. I found it better to just go ahead and get the tank you will need long term then to try and upgrade. to me I found it to be a lot cheaper that way.