How do you prevent a syphon?

[jeffaquarius]

Simple solution which a few people of posted, take the hose out of the water. Water stops, siphon breaks. No need for special equipment.

False since ATO level is above sump it works just like a U overflow siphon with gravitational pull.

 

[blert]

False since ATO level is above sump it works just like a U overflow siphon with gravitational pull.

Which is why you keep the outlet end of the ATO hose above the water level of the RESERVOIR and above the high water level (return pump off) of the sump (to prevent a syphon in the opposite direction).

 

[jeffaquarius]

Which is why you keep the outlet end of the ATO hose above the water level of the RESERVOIR and above the high water level (return pump off) of the sump (to prevent a syphon in the opposite direction).

This one works but much better instead of cutting the tube too short just connect a T tube connector on that spot and leave the horizontal part of the T open ended.

 

[chenzo9999]

I hope this helps - The problem is when the ATO reservoir's water level is higher than the pipe that delivers the water (as shown in the first part of the image) this creates a siphon - not a reverse siphon like normal, but a siphon in the same direction as the flow.

The fix is the raise the pipe so that it is above the ATO reservoir level. I use the PVC (as shown in the second part of the image) in order to reduce splash. The water just runs down the side of the PVC and mixes at the bottom of the sump.

I hope this is helpful.