This is my bulkhead layout for a new 120 gal
tank. The OF box is on the right and I'm using a closed loop system for most of the circulation.
The lower left hole (1.75) is the drain for the closed loop. The two top holes (1.50) are for .75" bulkhead fittings for the closed loop return.
The 1.50 hole on the box at the right is the return for the OF-sump-return line. Comments?? Does this look like it should? Thanks all!