Single drain Overflow System for a 55 gallón tank

[Andrés Garza]

Good afternoon, everyone.
I have a 55-gallon aquarium that I’m planning to convert into a marine setup. My idea is to drill a single 45mm hole, install a 1-inch bulkhead, and run the drain pipe down to the sump — without adding a secondary (emergency) drain. Would this setup be feasible? I’m asking because I saw a YouTube video of a 55-gallon tank using a very similar configuration: just one 42mm hole and no backup drain line. I’ll share the link below so you can let me know if this approach would work safely.

Please view the video

 

[wvned]

It will work fine as long as you keep the flow in the drain 200-300 GPH. I would make it a Durso. There are various designs that accomplish the same thing.

 

[Andrés Garza]

It will work fine as long as you keep the flow in the drain 200-300 GPH. I would make it a Durso. There are various designs that accomplish the same thing.

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My idea was to place a black acrylic storage box inside the overflow box. How could I adapt that idea to the setup you mentioned? Do you think it would actually work?

In the second photo, the pipe is positioned that way just to prevent water from leaking out of the tank. But tell me, could the system really work efficiently with just a single 1-inch drain?

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[wvned]

If you have a box with a bulkhead in it that is fine. This is made to work by placing a tee in the bulkhead on the back of the tanks and having a riser pipe come up to the level of the tank trim above the running level of the tank. The other pipe from the tee goes down to the sump.
The riser pipe is capped and a small hole is drilled. This is to quiet it.
The trick to making this work well is making sure air never gets trapped in it. The top is vented and the bottom of the overflow should be very slightly below thee water in the sump. You can even slant cut the bottom so one side is above and the other below.
All these things are to make it quiet so it doesnt drive you nuts gurgling and splashing. Water flowing smoothly and not fighting to push air bubbles down when they want to float and rise is the trick. Ideally all the air will come out the vent hole in the top and none into the sump.
Whenever you stop the return pump the overflow box and pipes will drain and fill with air. You want this air to easily leave again when the pumps starts again..