dosing pump vs powerhead venturi (siphon paranoia)

[D Ro Supafly]

I have a CPR CS 102 overflow, the model supposedly rated at 1200 GPH. Like the title says, I am paranoid about the siphon breaking since I've always used drilled tanks in the past.

After reading up on their site, they have a model that can use the Aqua Lifter dosing pump.

I can easily see how I'd set one up with this overflow, but would it be better to use a small dosing pump, directing the flow back into the tank or into the overflow, or would it be better to use the venturi from a powerhead?

 

[D Ro Supafly]

Okay, I got the Aqua Lifter AW-20 this morning, so I'll hook it up this evening for testing. I won't really leave the pump running full time until Sunday when I can watch it all day (Saturday, I need to build a canopy and the return puymp manifold)!

I'll post how it works once I simulate power outages/restarts and it is running full time.

 

[Rogger Castells]

Any way of sucking the little air that forms in the tubes will be enough to keep the siphon going, I've had overflows for years working and they never ever got locked because of air, I understand that current models are even more fool proof, so don't panic you could be watching the tube for a long time before you see anything.
if you are going to be sucking the air out with a pump I will make it go back in the tank definetely not in the back drain of the overflow box.

 

[D Ro Supafly]

I'm a retard.

I didn't understand how a siphon works, much less how a CPR overflow works.

I came home with the dosing pump.

I cut two lengths of silicone airline, one to apply vacuum to the siphon, one to dump water back into the display tank.

I disconnected the gang valve I had attached to the siphon.

I heard the gurgle of a breaking siphon.

I realized how stupid I am.

The siphon held as long as I had the valve on the air gang closed. Nothing would havce broken the siphon except for evaporation or dissassemnbling the equipment. As long as that valve was closed, I was golden.

At least I have a dosing pump now.