How to Mod a U-Tube

[KathyC]

This is a good way to mod a U-tube if you are using a hang on overflow box and a U-tube- rather than drilling a tank.
I never had any issues with this set up and used it on one of my tanks for about 5 years until I got a larger tank..that had a built in overflow.


This saves you from taking the change of getting a mouthful of SW and almost entirely eliminates the bubble that forms at the top of the tube and helps increase flow.


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This mod uses about 2 feet of regular air line, a small piece of rigid tubing that fits just inside of the air line tubing and a simple airline valve (all should be available at any lfs), and some good glue - I used Weldon.

The rigid air line tubing - cut a piece about 3/4 of an inch long.
Cut a section of airline tubing about 2 " long, and another about 2 foot long

Drill a hole in the u-tube so the rigid tubing JUST fits in it (be sure to remove all burrs from the rigid tubing after you cut it). Glue it in place. You want it to extend only the smallest about inside the tube.
Let it dry thoroughly.
Attach the short piece of air line
Insert the air valve
Attach the remainder of air line tubing.

Open the valve to suck out the air bubble from the u-tube, close valve once it is gone.
I usually just coiled the airline on the top of the overflow box when not in use. (don't detatch it :smile

 

[tunicata]

:sigh: Kathy, you just are always a major help.

 

[Dan_P]

This is a good way to mod a U-tube if you are using a hang on overflow box and a U-tube- rather than drilling a tank.
I never had any issues with this set up and used it on one of my tanks for about 5 years until I got a larger tank..that had a built in overflow.


This saves you from taking the change of getting a mouthful of SW and almost entirely eliminates the bubble that forms at the top of the tube and helps increase flow.


-------
This mod uses about 2 feet of regular air line, a small piece of rigid tubing that fits just inside of the air line tubing and a simple airline valve (all should be available at any lfs), and some good glue - I used Weldon.

The rigid air line tubing - cut a piece about 3/4 of an inch long.
Cut a section of airline tubing about 2 " long, and another about 2 foot long

Drill a hole in the u-tube so the rigid tubing JUST fits in it (be sure to remove all burrs from the rigid tubing after you cut it). Glue it in place. You want it to extend only the smallest about inside the tube.
Let it dry thoroughly.
Attach the short piece of air line
Insert the air valve
Attach the remainder of air line tubing.

Open the valve to suck out the air bubble from the u-tube, close valve once it is gone.
I usually just coiled the airline on the top of the overflow box when not in use. (don't detatch it :smile

What is the "glue" used to secure the rigid tubing to the U tube? Thanks for the nice demo.

 

[maviss]

smallest about inside the tube.
Let it dry thoroughly.
Attach the short piece of air line
Insert the air valve
Attach the remainder of air line tubing.

 

[Dan_P]

Thanks!

 

[TimberTDI]

Is it possible to add a HOB overflow to a tank that is already drilled?

My 60 cube's overflow sucks. It can only handle about 300 gph, my eheim 1262 is choked about 80% and I'm still getting a surge every 3-5 minutes.

I'm thinking adding a hob to increase flow. any thoughts?

 

[jaa1456]

Yes, just close off to the pre drilled holes in your existing overflow. They have bulkheads premade for that application. Then just go with the HOB overflow. But concerning HOB overflows, you will never need this mod if your sump is the right size to accommodate the water that will continue to flow. I had this setup on 3 tanks for over 12 years and never once had a sump overflow when the power went out.

 

[TimberTDI]

Yes, just close off to the pre drilled holes in your existing overflow. They have bulkheads premade for that application. Then just go with the HOB overflow. But concerning HOB overflows, you will never need this mod if your sump is the right size to accommodate the water that will continue to flow. I had this setup on 3 tanks for over 12 years and never once had a sump overflow when the power went out.

Can I run both overflows at the same time? I'm hoping to use one of the smaller hob?

 

[KathyC]

What is the "glue" used to secure the rigid tubing to the U tube? Thanks for the nice demo.

\

Sorry - didn't see this until today...
Use Weldon - not the thinnest type, but one of the slightly thicker ones. Not sure of the number, but I think it was 16.

 

[KathyC]

But concerning HOB overflows, you will never need this mod if your sump is the right size to accommodate the water that will continue to flow. .

The correct size sump is always suggested and the mod has nothing to do with the sump size - it is all about removing the bubble at the top of the tube without having to worry about sucking in a mouthful of SW

 

[TimberTDI]

- it is all about removing the bubble at the top of the tube without having to worry about sucking in a mouthful of SW

What's the worry about a mouthful of saltwater? How else are you supposed to check salinity?

 

[bertyboy69]

add an aqualifter to that little piece of airline tube directed back into the tank, and you never have to worry about bubbles again !