Auto top off forward siphon

[bla403]

All:
Is there a way to prevent forward siphons on auto top off containers?
When my auto top of turns on it occasionally siphons more water than desired into the sump.
The only way that has worked for me is raising the water tube to create more bead pressure that prevents the siphon.
Any thoughts? ( no the outlet is not under water)

 

[saxman]

We use 1/4" poly tubing with John Guest fittings for our ATO's. What we do is sit the pump in the bucket, and see where the water line is when it's filled. Then we cut the supply tube and add a "T" fitting above the water line with a short piece of tubing so we can "aim" the stream downward back into the water (the end must not be submerged in the bucket). When the pump stops, the above water tubing acts as a siphon break, thus preventing the "forward siphon" you speak of.