I do not agree with the previous posters. A 180 gal. 72 x 24 x 24 built with .375" plastic is barely adequate for Freshwater, and if you are thinking about a reef with 1.026 SG, and 82+ F. temp, you will be looking at a bellied out tank at best. It is always your call, but I feel it would be a better sump.
I put a value on a dry floor, and animals that have been taken from the wild, and placed in my care.
Barrier Reef has a 180 for sale, that I built and it is all .500. I also offer a .750 front panel upgrade for individuals that desire a zero flex front.
But what do I know, just my .02.
Jason Gregory