So glad I didn't use a check valve to the bog

[twoheadsbrewing]

So I was almost through my bog build, with the plumbing already glued up and thought "oh &*%^, what about a check valve". I decided that I could add it later, but happened upon this video:

Basically, it's a siphon release which when the water in the bog gets below a certain point it starts sucking air. And that kills the siphon and prevents the bog from emptying into the pond. And he makes a good point that check valves are mechanical and will at some point fail. And then you have to cut out the valve, maybe do some digging, reinstall, check for leakes, etc. But with this simple method, it not only saves money and work, but will always function.

Being super thrifty(cheap?), what I did is simply drilled a hole in the PVC feeding the bog just under the surface of the water. It doesn't need to be a large hole; air will get in the line once the water drops and will stop the siphon.

 

[Lisak1]

That tip has been shared here a few times - it's a good one! We installed a ball valve at the point where the line enters the bog. We can open or close it to control the water flow or shut it completely to keep the bog from emptying. We do have a check valve ahead of the pump, so it wouldn't go far, but like you said - check valves are prone to failure so it's a good fail-safe. It does require us to know it needs to be closed, but otherwise it's a pretty simple solution.

 

[mrsclem]

I have that done in all my filters and in bog!

 

[Jhn]

Yep definitely a good tip, learned that tip years ago with reef tanks and overflows drilling holes in the tubing to keep the sump from overflowing.

 

[combatwombat]

I have that detail planned for my bog, and then I thought: why not just plumb that anti-siphon valve to a little rock bubbler or something? Why not get another little feature out of it?

 

[Rashad]

If my pipe that takes water into the bog goes above the water level of the bog I don’t need to worry about this right? I do have a check valve.

 

[mrsclem]

My pipe for my bog goes from lower pond up over the bog wall and then down to bottom of bog. I have the hole drilled right at the water level in the bog.

 

[Rashad]

My pipe for my bog goes from lower pond up over the bog wall and then down to bottom of bog. I have the hole drilled right at the water level in the bog.

Since it’s the first opening to the bog doesn’t it push out quite a bit of water at the surface of the bog where you don’t really want it? I guess if it’s a small enough hole it will be limited.

 

[Jhn]

Since it’s the first opening to the bog doesn’t it push out quite a bit of water at the surface of the bog where you don’t really want it? I guess if it’s a small enough hole it will be limited.

No not really.....but it will depend on how big you make the hole. You are just drilling a hole in the pipe so it will suck air, obviously too small of a hole will clog easily, defeating the purpose. the hole I drilled is right at gravel level in my bog but above water level I can’t even tell water is coming out of it.

 

[combatwombat]

If my pipe that takes water into the bog goes above the water level of the bog I don’t need to worry about this right? I do have a check valve.

It will still siphon.

 

[mrsclem]

I tried 3 different check valves and every one failed to keep the bog from draining so out came the drill! 3/8" hole, I do get some water spraying out but a well placed rock until the plants cover it .

 

[addy1]

If my pipe that takes water into the bog goes above the water level of the bog I don’t need to worry about this right? I do have a check valve.

It will still siphon.

My input pipe is about a inch above the bog surface, It never siphons the water out when the pump turns off. External pump