Tom's Aqua Lifter question

[MKLKT]

I'm wondering if anyone has an answer to my query...

I'm in the process of setting up an ATO so that I can make life easier for myself and was going to snag a JBJ controller and an Aqua Lifter to go with it. My situation is that my reservoir would have a waterline that is above the waterline of the sump so I need to know if the Aqua Lifter creates a syphon while OFF which would cause the sump to be flooded. Does anyone know if this is the case or know of any other pump/powerhead that can be used that blocks flow while off?

I've tried searching to no avail.