Check valve ?

[Fb7782]

Working on my pond design. If the bottom of the bog filter is above the pond level do I need a check valve on the bog input line. I would like the output of the bog filter to make a stream back down to the pond. Incase of a power failure I don't want the bog muck to back feed into the pond. Thanks in advance.

 

[brokensword]

in theory, yes. That said, you can just drill a 1/4" hole in any plumbing going INTO your bog from the top (plumbing has to be higher than your bog surface water level) and that will break the siphon when you turn off the feed. The small amount of water that might leak there will be contained by the bog, so no issues. There's also some sort of breaker vacuum type thingy, you'll have to ask @GBBUDD as I can't remember the exact name/details.

 

[GBBUDD]

You got its just backwards it's a vacuum breaker available at any hardware store it's the exact same principle as a check valve it's just reverse action . The valve closes in a power outage with a check valve. But a vacuum breaker opens Ina power outage thus allowing air into the pipe

 

[brokensword]

You got its just backwards it's a vacuum breaker available at any hardware store it's the exact same principle as a check valve it's just reverse action . The valve closes in a power outage with a check valve. But a vacuum breaker opens Ina power outage thus allowing air into the pipe

potayto potahto...

 

[teckpham]

I use this one:
https://www.bunnings.com.au/deks-air-admittance-valve_p4780031