EMS overflow plumbing

[iGotJokess]

I have an EMS overflow box and was looking for a little advice while plumbing. I have the emergency line cut to about an inch below the top of the box, my full syphon is plumbed about an inch from the bottom of the box. My question is about how tall should my open line be? I’m using 90’s for the open and full syphon.

 

[iGotJokess]

Here’s what i have so far. I believe my open drain is too low?

 

[Coolcasino]

That looks good to me. I would drill a hole on top of the elbow to the middle line as you don't want that to be a full siphon. I actually only have an elbow on my full siphon line. Water level is a 1 inch from the middle line.

 

[Coolcasino]

I actually got the lines mixed up. You could raise the middle line more that way you minimize splashing. Also give you some elbow room to control the level in the box.

 

[BrandoNy]

Mine is 1 1/2” from the top of the box. It has been running silently for a year with no issues.

 

[iGotJokess]

Mine is 1 1/2” from the top of the box. It has been running silently for a year with no issues.

Would you say it’s roughly half inch below your emergency drain then?

 

[BrandoNy]

Emergency drain is 1 1/8” below the top of the overflow, so 3/8”.

 

[iGotJokess]

Emergency drain is 1 1/8” below the top of the overflow, so 3/8”.

Awesome appreciate you taking the time. Thank you

 

[ca1ore]

My rule of thumb always was to have the top radius of the secondary U (or dual elbows) about 1/2” below the top rim of the emergency. That way, the secondary can run as a siphon if necessary without triggering the emergency. I also increased the diameter of the emergency to 3”.

 

[WvAquatics]

That's about how mine looks.

 

[iGotJokess]

Update: Can’t see but there is a hole drilled on the open line

 

[Coolcasino]

Better!

 

[BrandoNy]

I do have a hole drilled on the top of the open elbow.