first time setup question

This may be the silliest question of the day.

When I shut the power off my sump fills to the point of overflowing and qould overflow if I didnt turn the pump on.

Is the a balance so that if the power was to go off the whole system wouldnt overflow?

 

Ball valve. You can get them at the hardware store.

Another simple solution is to drill a small hole in your return about 1/2 under the water line on the return line inside the tank. then as it back drains the water level will go low enough it will suck air in and break the syphon.

 

Thank you. If I have already run my PVC is there an easy to install fix? Can I place it on the overflow?

 

You are supposed to leave room for backflow from the DT. You can minimize this by having your return nozzle just below the surface so air will stop the reverse siphon quicker.

Also you can drill a hole just below the surface in the return line.

 

There are no silly questions here. But there is also a search option that will answer almost every question I have ever had. Check this out....

http://www.3reef.com/forums/reef-aquarium-articles-how-tos/all-about-sumps-filters-fuges-79852.html

 

The return is where you want to put it. Once you loose forward pressure the water will back feed down thru it. Yes water will continue to run down the overflow as well, but that is what it is designed to do, so anysort of break you install there will effect it during normal operation.

 

A ball valve might not be the best solution and I would not recommend relying on the anti-siphon or siphon break holes you can drill in your return plumbing.

A more reliable method is to move your overflow inlet higher. If it's an adjustable overflow (hang on back style) then just move the box up in level so that the water lever in the DT is increased. This will keep more water in the DT and when the pump goes out there will be less water to overflow into the sump.

You may also have the level in your sump to a point where it is also too high - did you build your sump?

There are a lot of considerations when designing a sump which must me made. The most important is preventing accidental overflow.

My sump is designed such that if the power goes out, I have a small calculated volume of overflow into the sump - this is further safeguarded by keeping my return nozzles near the surface of the water this way they cannot siphon half the tank accidentally. They also help with surface agitation in this position.

I also have the sump designed to take the full volume of my ATO reservoir, again, in the case of catastrophic failure of my ATO system, I will still not have a flood.

Hope this helps . . . .