Overflow Problems
 

Due to Lack of patience and experience when I first got my tank I didnt bother to get it drilled and used an overflow box. MY overflow u tube is gravity powered. I have recently upgraded my setup, in my old setup I had my return pump at such a level that wouldnt allow flooding of my tank in case the u tube lost it's siphon unfortunatley my new setup does not allow this. Is there any way I can hook up a power head to my u tube to suck out air and prevent a siphon loss? or to be able to recover on it's own in a power outage?

A properly designed and running u-tube HOB overflow, such as a Lifereef, won't lose its siphon.

You could also install a float switch to turn off the return pump in the event your siphon breaks.

Rich.......

I installed a float switch just in case and I use a Tom Aqua Lifter pump to maintain my siphon. I pulls air and or water. However fkshiu is right, if the u-tube works properly it won't loose siphon.

Went drilled returns myself but have seen a picture where the top of the overflow box's "u" is drilled and has a piece of airline attached with the other end of the tubing connected to a venturi port of a Maxijet sitting in the tank. Idea was air that might buildup in the top of the "u" is continuously removed and when power is returned (after an outage) the Maxijet is to help restart siphon. Couldn't see the Maxijet having that much suction but that was the concept.

Yep, I have a cpr-style overflow that uses this concept and it works great.

For my DIY CPR style overflow, I have 2 x 1" U-tubes, and they did lose syphon sometimes (after a power outage or manual shutoff).

The problem was that the intake of the tubes on the inside of the tank were not always 'level' with each other. In a perfect world, both tubes would just kiss the surface of the water, maintaining a bit of suction for when the power came back on. But in reality, one tube may be higher than the other, so when the water level was low, the higher one would end up sucking in air and lose syphon, ending up with an empty U-tube. When the power came back on, that tube was not syphoning anymore, therefore the overflow couldnt keep up with the water being returned to the tank.

Since then I've drilled holes in the tops of both u-tubes and installed an Aqualifter. Now no matter what, when power comes back, it sucks out all the excess air in the tubes to restart the syphon.

Better safe than sorry.

Great ffedback looks like I'll either go with an aqau lifter or an try attaching a tube from a power head to the u tube.

Might be of interest, link shows graphically how siphon is maintenance during power outage in a properly designed HOB overflow.

http://www.melevsreef.com/allmysumps.html