Reverse check valve as a siphon break!

[AlanM]

I'm not sure if this is an original idea with him, but Melev is the one that posted it recently.

 

Coral Magazine just posted this to facebook, but it's brilliant.  I even think I could do it on my tank without too much trouble.

 

 

Basically, the water pressure of the return lines holds the check valve shut when the system is in operation and if you shut off the pump the check valve opens, lets in lots of air, and breaks the siphon.

[YHSublime]

Brilliant. Thanks for sharing! 

[davelin315]

Bad idea in my book... all it takes is some crud to come up with the water when the power comes back on to prevent the check valve from swinging closed.  That's why I never use them in any aquarium application - there is too large a margin for error.  Looks neat, but neat looking ideas aren't always ones that will work long term.  I haven't looked at the link to see whether there's anything that would prevent what I see as an issue, but will take a look later.

[AlanM]

The margin for error is that he has it pointing back down into his tank, so worse case is that he's got another "return" nozzle that makes lots of bubbles in the display because it fires water down through an elbow into the tank.  

 

Also, it's right on top so he can screw it off and clean it easily and since there isn't routine water flowing in it, the crud doesn't build up so much.  Devil would be in the details for this one.  It works fine for his arrangement, but if I tried to hide it behind the tank or some place that wasn't visible I can see it spraying water all over when it failed to shut when the return nozzles come back on.

[zygote2k]

Check valves, if cleaned and serviced regulaurly are as reliable as most any other piece of valving in a conventional plumbing run.

Many large systems wouldn't work properly without a check valve.