ATO pump creating siphon?

kkgaskin90 · May 19, 2015

Is it possible for the topoff pump from the reservoir to the sump is creating a siphon? It came on as it was supposed to, then switched off, but water kept flowing. What can I do to remedy this? I'm sure there's an obvious fix, but I'm a terrible handywoman

broach · May 19, 2015

Hard to explain. But check to see if the line is lower than the water at its max in the reservoir. If it is it will need to be the same level. Do you have pictures?

143MPCo · May 19, 2015

is the top off tube in the water?
What height do you have the ATO (water) container at?

VFR_Mayday · May 19, 2015

Even out of the water it creates a siphon. You need a back flow check valve. That will fix it. I had the same issue.

kkgaskin90 · May 19, 2015

Out of necessity due to space restrictions the pump in the reservoir is definitely below the max water level of the sump. And it's not flowing backwards, it's still flowing from reservoir to sump. Will a check valve stop that or no?

Mat1018 · May 19, 2015

If the discharge hose is lower then the top off then it will create a siphon. All you have to do is lower the container or just move the hose so the end of it is higher then the container.

VFR_Mayday · May 19, 2015

It did for mine. So I had pump in ato trash can. On the bottom of the can. The hose ran down to the sump in the filter sock. Even when the pump turned off the water, due to the water line in ato can being higher than sump, would continue to flow. I installed a backflow check valve and it solved the problem. You could run it up to the overflow for now if you can't get a check valve.

143MPCo · May 19, 2015

Mat1018 said:
If the discharge hose is lower then the top off then it will create a siphon. All you have to do is lower the container or just move the hose so the end of it is higher then the container.

Agreed!

Fin · May 19, 2015

I have done this on two tanks and it is an easy fix. I use a piece of rigid tubing (mounted well above the sump) and run my line from my ATO pump into the side of the tube. The tube runs down into my sump. The open end of the tube prevents a siphon. The water from my ATO just runs down into the sump and shuts off when the pump does.

Here is a pic of a small tank I am working on now. The rigid tubing is shown to the right of that media reactor. I drilled a hole in the side of the tube and inserted my ATO pump hose (with the use of a cheap air line fitting). I had to do this because my reservoir is on a shelf above my sump. I didn't want to put a float valve in the sump to gravity feed.

kkgaskin90 · May 19, 2015

Here's my ghetto setup: ATO reservoir on the right. Pump sits on the bottom. Feeds in to skimmer compartment on far left. End of hose is not under water.