Question for the beananimal overflow experts

[ScubaSteve]

Originally Posted by Tyler Werbowski

Thanks guys. In summary:

1. Main drain fully submerged with a strainer 3-4 inches below the secondary drain.
2. Secondary drain has a T fitting followed by a down turned elbow to set the height of the overflow box (2 inches below the water level of the main tank). Airline tubing (as in picture) coming out the top.
3. Emergency drain with a T fitting and an upturned elbow (to allow stop water from flowwing when your arm is in the tank). Cap the emergency drain to make it air tight?

1. No need for 3-4". 1" will suffice. I'd say 2" tops.

2. Correct, though it doesn't have to be 2" below. To low and it splashes; too close to the top and you might have issues with overflowing the box if the water level changes suddenly (again, arm...). Mine is 2.75"-ish below the surface doing 600 gph on a 12" wide overflow. No splashing.

3. Emergency drain: don't cap it to make it air tight and no need for a T or elbow. Just run a pipe straight up and have it a bit above the normal water level.