Check Valve

[chazotte]

How do you prevent water from siphoning out of your tank and back into the sump when the power goes out?

I’ve done this by keeping the return pipes towards the very top of the tank. This way, as soon as the water drains a little bit, air gets in the return line and breaks the siphon.

Is there a better way to do this? Some type of check valve that could be incorporated?

Ken.

 

[paintballe48]

If you drill a small hole toward the top of your return you can keep the mouth of it as far down as you want too. Look at this picture it should help you understand.
http://www.dskidmore.com/~denise/aquarium/DIYPlumbing/AntiSiphonHole.jpg

 

[Hawkeye]

i was under the impression check valves are notorious for failing...

The hole in the return line is interesting but i'd be concerned about a blockage (salt creep).

Overall I don't know if any "single" solution is as fool-proof as having enough room in the sump to handle any siphon that might occur. If you split the return at the top with a locline T - with one close to the surface and the other in the area you want it - then you should be ok. Any siphon would break with the higher split T.

At least - that's how I set up my 120. I don't have a hole or a check valve.

 

[paintballe48]

i use the hole and it works good for me, no salt buildup either

 

[chazotte]

Thanks guys. Both are great suggestions.

 

[Mbodell]

I would do both. I only have the hole, but there is not harm in doing both.

 

[rarena]

There are some high quality check valves. The return line placed well above the overflow
is probably the safe bet.

 

[DaveK]

I've tried two different types of check valves. I considered them to be of good quality, and I did test the end result. Initially they did work. However, like anything in a reef over time they develop heavy bacteria films and collect other material passed through the filtration system. The end result was that they failed when it was critical. The other downside it that a check valve will reduce some flow through the pipe, but this is minimal.

Yes, they might work if you are religious about cleaning them, but I would not want to depend on a check valve in an aquarium installation. The methods of letting air into the return when the water level drops all work well, and avoid the use of check valves. Bottom line is save your money.

 

[daveh285]

i was under the impression check valves are notorious for failing...

The hole in the return line is interesting but i'd be concerned about a blockage (salt creep).

(/quote]

You also don't have to worry about salt creep or blockage because as long as your return is pushing water it will also push water out this small hole.