I have a sump for the 125 so this one is up for sale. It's 12 inches wide 29.5 long and 17 tall at it's highest. Setup for a dual overflow, but surely could be modded. If I did my math right makes it about a 25 gallon or so sump. Would like to get 100 or best reasonable offer for all of it. Also into trades. Still need a light(s) ATO and powerheads for the 125 aggressive build.