Work in progress 180

If I'm thinking right, a 3 might be a little small for a 180? Not overly familiar with them. What kind of flow rate are you looking to move through your sump? I've got close to the same setup with 1.5 drains. Running a 40b sump and a dct-12000 at about 50% power. Much over that and it creates a lot of turbulence in the sump, water cascading over the baffles by about an inch lol.

 

Looking good so far. If you don't like the Aqueon. Have you considered making your own?
I usually go out and find a cheap aquarium. Then reseal it and leak test. Put tape or marks on side to get layout. Then measure and call glass shop and they cut for me.
Seal them in and good to go.