Awesome! I am also in the process of getting everything for my IM 40L before I start cycling. I bought the Tunze Comline DOC Skimmer 9004 but I measured the rear sump and I don't think it fits. I haven't opened the box yet because I want to be able to return it to BRS without being charged their open box restocking fee. Could you confirm? Thanks.
Following along.. starting an IM 40L build as well!

AIO Build - .Marshall's IM 40g build
Hi all, My name is Marshall and I’m back after an 8 year hiatus, I live in Minnesota. My old build thread: https://www.reef2reef.com/threads/my-first-tank-build-75g.86312/ I built a new house in 2018 and had a room designed next to the bar area in my basement specifically as a fish room. I...
