Anyway to stop a siphon after power outage?

[ThatNewFishGuy]

I was just wondering if there was any pieces that I could attach somewhere in my system's plumbing to stop a siphon or to block it somewhere along the line before my sump starts overflowing.

My tank has an internal overflow box in the corner. When the power goes out, water from the overflow continues to drain into the sump for a little bit (im using a draino standpipe, so it has some height to reach in the overflow box before it drains into the sump). The main problem is that since my return line is submerged about 3 or 4 inches below the surface of the water, everything from that point up gets sucked back through it because of the siphon. If me or my dad aren't home to run up to the tank and raise the return line out of the water, its a big mess.

I tried raising the return line a little bit when the tank is running normally but it causes too much water splash on my lights. Since my sump is only a 10 gal it gets filled up pretty quick.

So is there anything that would stop or block a siphon when the power goes out and no one is home?

 

[wesleydnunder]

Drill a hole in the return line just under where the normal surface of the tankwater is. When the power goes out and the return attempts to siphon backwards, the hole will allow air into the line when the surface falls below it, stopping the siphon. It's called a siphon break.

Mark

 

[XanAvaloni]

no idea. This is wny I've never had the nerve to set up a sump or refugium or anything requiring moving water from one tank to another. Plumbing already in place I can figure out and maintain and repair. Creating new plumbing is a journey into the terrifying unknown for me.

best of luck. I'm sure one of the less plumbing-impaired of the Marine department will be by shortly with useful advice.

edit: or already has been.

 

[Narwhal72]

The siphon break is one way to stop the backsiphoning through the return line. Or you could install a check valve in the water return line so it can only travel one way. Downside to check valves is they need to be periodically cleaned to prevent biofouling and certain types (spring types) put a lot of resistance on the water flow and slow down the water flow to the tank dramatically.

Andy

 

[greech]

Yep, sipjon break or check valve. If you have locline (or something similar) on your return line that allows you to adjust the position of your return output, you may be able to simply raise that output point right up near the water line in the display which would limit the amount of water that has to drain before the siphon breaks. This of course assumes that your flow rate is low enough so that you don't have a jet of water shooting out of the top of your tank. I don't rely on my return much for flow in the display so this is how I have mine setup.

 

[Khemul]

The most fool-proof method is to make you sump large enough to handle the water.

If that isn't possible then the siphon break concept is a good second. Just make sure to do regular maintenance on it since it can fail if left alone long enough (buildup can block the hole rendering it useless).

 

[ThatNewFishGuy]

Wow the siphon break is genius! I wish I had asked earlier lol. Thanks Mark!

Im using something very similar to locline Greech, but the flow coming from it is pretty strong. Furthermore my lights are only about 3 inches off the surface of the water so they get very tiny splashes which arent so bad first but may cause salt creep over time.

I would love to upgrade the sump. But my tank is a 90 corner and finding a larger sump that fits under there (and also accomodates my aqua c urchin pro skimmer which is tall) has been such a pain. The check valve is interesting but I dont like the idea that flow may be restricted.

Siphon break will be one of my weekend tasks.

EDIT: will the siphon break hole cause microbubbles or anything? about how big in diameter should the hole be?

 

[greech]

Shouldn't be any significant bubbles as long as the hole isn't too close to the water line. I would drill two (one on each side) just in case one clogs. They don't need to be very big.

 

[wesleydnunder]

Shouldn't be any significant bubbles as long as the hole isn't too close to the water line. I would drill two (one on each side) just in case one clogs. They don't need to be very big.

Yup, about an 1/8" hole on either side is fine. Just need enough for it to suck air.

Mark

 

[Amphiprion]

I would use a few different things to serve as redundancy in case this happens, since many of them can fail. Personally, I use a flap-style check valve (I've had these fail before), a siphon break (these clog if not cleaned from time to time), and making sure my return isn't too deep in the water. This ensures that I never have a problem, since I have a small sump due to space restrictions.