Preventing Return Back Siphon Inexpensively And Reliably

[wsboyette]

I have discovered a means of preventing back siphon and subsequent sump overflow without having to purchase an expensive check valve of questionable reliability. As is obvious, it would only take a tiny bit of debris or buildup in such a valve to cause it not to seal completely and cause a flood. A tiny hole drilled in the return at the minimum desired water level inside the tank is enough to prevent back siphon without fail (1/32 - 1/16" is enough). During normal operation, the hole is submerged and (due to its tiny size) reduction of the flow at the return's output is negligible. When the level of the tank drops to the hole during power down, air will be admitted to the return and the siphon will be broken. I am using this on my Berlin setup, and it works great ! Easy maintenance too.... Instead of dismantling and cleaning a check valve, a ***** of a toothpick at water change time is all that's needed to ensure continued reliability.

 

[allsps40]

I drill a small hole in my return outlet right below the water line. It has worked perfectly for 4 years.

 

[Toddrtrex]

I just have my return line high enough, and combine that with enough space in the sump. Little holes can/will get blocked.

 

[hotrodolds]

if you simply drill the small hole on the return just ABOVE the waterline then you will always know whether or not it has been blocked

 

[scarface70706]

simple check valve and small drilled holes in my 90 elbow in the overflow box has been working great for me. i just keep up on my cleaning on the tank and always look to make sure the hole is not clogged.

 

[doonan75]

The return outlet I bought in 2004 already had the hole drilled. Did they stop making them that way or did you make your own?

 

[bellis31]

I just have my return line high enough, and combine that with enough space in the sump. Little holes can/will get blocked.

This^.... I have 8G space in my SUMP for back siphon and my return is about an inch down from the top of the water, I could easily go deeper if I wanted to with the return. Tested several times and works great!