Plumbing question

[Ronfire]

I am looking at bog that is higher than the pond and worried about the water siphoning back if the pump stops. I could use a check valve but they add restriction and can fail. If I have a high point in the plumbing going over the top of the bog liner can I use a plumping vent to let air in when required. I don't know if they will work for the water pressure against the valve while operating. I don't think there would be much pressure as it will be at the top of the bog.
Thought I read about this setup but cant find it.

 

[mrsclem]

I have found that a vent pipe doesn't work well in my system. The water tends to go up the vent rather than thru the bog. I drilled a small hole in the inlet line right below the gravel level. It does spray out some water but that can be covered with extra gravel. If power is lost, as soon as the water level drops below the hole, siphon is broken.

 

[MajorDan]

Interesting. I have a vent in my bog and the water level in it is at the water level of the bog. I have a 3000+ gph pump with 2” supply lines to bog and in the bog. The water is split between the bog and a bio waterfall. If I close the valve on the waterfall the water fairly boils up out of the bog.

 

[mrsclem]

I'm only running 1600 thru my bog, all 1 1/2" piping.