Modular Marine 2400 Overflow

[WVReefJunkie]

I dont have any instructions for the plumbing inside the overflow. I understand there is a primary, secondary and emergency drain, but not sure the height and appropriate fittings to plumb those. Thanks

 

[Gablami]

While not exactly a “bean overflow” this is what most people would do for a three pipe overflow. Take a look:

 

[ca1ore]

Lots of different ways frankly. Primary siphon can be as simple as a screen threaded into the bulkhead (which is what I do) or some form of a U. The idea is to get the mouth as far from the surface as possible to prevent an air vortex. Secondary should be a standpipe topped with a U. I drill a small hole in the top to prevent airlock. The bottom curve of the U will set the water level in the external box, so adjust height accordingly. Emergency should be slightly higher than the top curve of the secondary, but no closer than 3/4” to the top rim of the external box. I always upsize the pipe diameter on the emergency.