electricity out....HOB overflow...Screwed?

[blennymower]

I've always wondered.....and this is for those who have hang on back overflows. When the electricity goes out causing the siphon to break what happens when the electricity comes back? Does the overflow creat a siphon by itself or are you...screwed?

 

[sjm817]

The siphon does not break when power is off. Everything resumes running when power comes back on. At least it does with a good properly set up overflow.

 

[blennymower]

I don't understand. If the power goes out then the water level will drop since no water is being pumped this will eventually lead the overflow to suck air and break the siphon. Right?

 

[sjm817]

No. The U Tube stays full of water when the power is off. This is done either with a baffle or a standpipe in the rear box and the skimmer box in the display. There is no place for air to enter and break the siphon. The siphon is maintained when power is lost.

 

[Toddrtrex]

To add what Scott has said --- which I agree with completely.

I have been using a LifeReef overflow box for about 7 years now, I shut off the main pump weekly (( water changes )), which is just like a power outage, and have never lost siphon.

Granted, now I do because I cracked the U-tube while cleaning it --- 100% my fault. The duct tape I put on it isn't holding as well as I would like, need to get a new U-tube.

 

[becact]

Even with the power off, the water level on both sides of the overflow box is still higher than the submerged ends of the U tube. So you keep your siphon When the pump comes back on everything will work as before.