Overflow question about air bubbles.

[viperman100]

I've never used an overflow box before and was wondering, how do you get all the air out of the u-tube, the only other time I used a sump filter my tank was drilled on the back and I've also used the DIY pvc overflow but never a box type. PLEASE HELP ME OUT

 

[DragonKeeper]

You can put an aqualifter on it. Drill a small hole in the top of the u tube and either valve or run a line to an aqualifter.

Keeper

 

[ar0wan]

I ran an overflow box for years by running airline hoseing up the u Tube and manually siphoning out the air to get it started. Once it's almost empty I just cap the tube with my thumb and pull it out; the pressure expels the remaining bubbles out the back. Kindof unorthodox but with no valve hole (that EVERYONE uses mind you) there was no way for the syphon break. I had cut an extension for the u tube so when power was cut it would stop the syphon but not empty or break it. same restart theory as the DIY overflow.

 

[nfored]

I ran an overflow box for years by running airline hoseing up the u Tube and manually siphoning out the air to get it started. Once it's almost empty I just cap the tube with my thumb and pull it out; the pressure expels the remaining bubbles out the back. Kindof unorthodox but with no valve hole (that EVERYONE uses mind you) there was no way for the syphon break. I had cut an extension for the u tube so when power was cut it would stop the syphon but not empty or break it. same restart theory as the DIY overflow.

pictures?