This is the overflow box that I got. The craftsmanship is excellent. Originally I bought a Synergy Reef Shadow, but unfortunately, at 16", it was too wide to fit my AP700 arms. I must say the the acrylic Modular Marine feels much more sturdy than the ABS molded Synergy.
https://modularmarine.com/collectio...-low-profile-overflow-box-with-removable-weir
I upgraded from three 3/4" uniseals on the bottom of the exterior box to three 1" bulkheads. Admittedly, that leaves space for the plumbing inside of the exterior of the box very tight.
I haven't drilled my tank yet so the protective adhesive paper is still on the overflow box
Overflow box 2
Acrylic lids come standard on both the internal and external box.
Overflow box 2
I will have it set up so that the going from left to right will be the main siphon, secondary drain and emergency drain. The emergency drain will drain into the skimmer section of the R-200. Because of the cramped quarters, the main siphon will just have a flat strainer.
Pipes
Here is the external box with the plumbing. I still have to drill the vent hole in the secondary drain elbow.
Exterior Box
The friction fit removable exterior box for cleaning and maintenance is a nice touch.
removable weir