View Full Version : Plumbing Ideas Tight External Overflow Box

07/10/2015, 03:43 PM
Hey everyone,

I'm having an issue here...

On our new frag tank, the overflow box is a bit tight for 1 1/2" plumbing.

Originally I had planned to do a Bean Animal style drain like I have on our display tank, but after getting everything together there is no room for 1 1/2" 90s to create a full siphon.

I'm curious given what I have to work with, what my choices are to quiet the system down?

Are there some low profile elbows/tees they don't sell at the hardware stores that I could try?

Something else maybe off the wall I haven't thought of?

Any help would be great!

BTW: The drain lines are about 4-5" under the water line in the sump.

Here's a video to help illustrate my issue...


Thanks! :beer:

07/10/2015, 04:31 PM
Reducing 1.5" to 1" tee with a 1" street elbow and 1.5" cap on the vertical?

Remove any pipe inside the box on the siphon and hope water level is high enough to prevent it sucking air? If not put a sheet of something above it on eggcrate to make the distance longer to reach the surface?

Lots of options really, since elbows aren't necessary really. All you need is to prevent it sucking air.

07/11/2015, 09:31 AM
Thanks :)

Finally got a bit of time to play with it.

Using the hand over the drain "technique" ;) I found out the far drain had almost no suction.

So closing the near drain a little and opening the far drain more made the drains a lot quieter.

Now I just need to play with water levels to reduce the water going into the emergency and we should be good :)


07/11/2015, 09:37 AM
The drain should be silent. Are you still experiencing noise?

07/11/2015, 09:46 AM
The drain should be silent. Are you still experiencing noise?

Not in the drains, just the emergency.

07/11/2015, 10:03 AM
Oh gotcha. I tend to type before I read :)

Keep on tuning :thumbsup:

07/11/2015, 09:43 PM
Getting there... just overflow noise now.

It's pretty quiet and in a low traffic room, think it's a pass :)