Yes, its the outside diameter, fits perfectly in there.
you can see the drilled holes in the bottom, i also added an extender to bring it to the overflow but you won't need it since it's draining back into the sump.
Looking great.. Nice use of the 90.. Have you thought about your aquascape?
very interested to see how these lights look on this size tank. i considered them couple months back. so ill be looking for updates sir. lol...
Atomic bought the setup from me, and it looks like he has corrected all my screw ups! Lol
As far as the lights I was more than happy with their strength. I was able to run the lights at a max of 50% and my corals on the rock and the sand all showed good growth.
Build is going great! Almost as impressive as the redo of the house :dance: