ATO reversed flow

[Ranchu50]

Thank you very much.

I’ll make sure to lift/elevate the tube and make sure it has no contact with water.

[Ryancw]

a great way to do this while still having it silent, unable to splash all over the place and not get accidentally bumped out of place is have the ATO tube dump into a peice of PVC standing vertically with the bottom below the water line. the open top of the PVC will still allow air in to prevent siphon

[hfp75]

It’s a back siphon....

I had it happen one time, overnight it drained 1/2 a 65g tank... I quickly acted and saved it all, but lesson learnt......

Not again....