If you click on the pix, it will enlarge.
I cannot use Paint so please pardon the scratch.
Will this pipe layout work for a 120 gal
Red 1" Open Channel
Yellow 3/4 " full siphon
Black 3/4" return to tank
Green 1" Emergency
Using a Sicci 4 40 gal
There is a dam that came with this tank that is used to baffle the overflow to keep water out if so desired. I am using it on the left overflow to prevent stagnate water there because of no flow in that chamber