Siphon Problem on ATO

[gort]

I feel like this is a dumb question, but i want to pose it to you without me trying several iterations that fail...

Siphon. I have an ATO, and part of my sump is the topoff water. Built right in to the sump, so it sits at the left end of the sump. Just to the right is my mag return pump.

The water depth for the mag return compartment is say 5 inches. When I fill up the topoff water compartment its depth is say 24 inches.

I have a pump in my topoff compartment that turns on when the float valve in the mag return compartment gets below the 5 inches of depth.

Pump turns off when this level is reached again, 5 inches. I have a hose from the topoff water pump over to my mag return pump compartment.

The hose comes from the pump at the bottom of the topoff water compartment , over the divider , into the mag return pump compartment and the hose now goes all the way to the bottom under water in the return compartment.

So I fill up my topoff water compartment to 24 inches. Water drops below 5 inches in the mag return compartment, then off when it reaches the 5 inch depth again, and I get a big siphon until i fill up the sump and the water levels are equal.

This has to be easy for this crowd. Should the hose outlet into the return compartment always be higher than the water level in the topoff water compartment??? I have heard about cutting a little hole in this tube over in the return section above the water line...

What do you think is my best bet?

Thanks in advance.

 

[johniii]

You could put a hole in the hose right above the water line of your ato. move the hose out of the water on your return side. when the pump goes off the air whole should break the siphon.. Make sure the hole is facing the water to avoid spillage.

 

[snowmansnow]

it isn't foolproof.. but use a check valve

b

 

[smallblock]

no just put the hose up out of the water. That way it has no way to siphon. Do you understand what I'm trying to say here. Hang it above the max water line in return section.

 

[reeftankjunkie]

I beleive what he is saying is that the top off water wont shut off, even though the float valve is closed and it continues siphoning water from the top off over to the return section. You would have to drill some sort of hole in the tubing from the pump to the return section, otherwise it is always going to equalize both sides when the pump shuts off.

Edit: Nevermind.. just re-read it. the easiest would be to have the hose going into the return higher than the ATo compartment...I'll be quiet now

 

[grouper therapy]

I need a pic of this. I'm not following the hose underwater thing

 

[gareefer]

Smallblock;692567 wrote: no just put the hose up out of the water. That way it has no way to siphon. Do you understand what I'm trying to say here. Hang it above the max water line in return section.

Do this.

If the float switch is set to stop the amount of water in the return section at 5", put the end of the topoff hose going into the return section at 6" or 7". Don't let the end of the topoff hose get under water and it will not be able to siphon.

 

[grouper therapy]

GAreefer;692600 wrote: Do this.

If the float switch is set to stop the amount of water in the return section at 5", put the end of the topoff hose going into the return section at 6" or 7". Don't let the end of the topoff hose get under water and it will not be able to siphon.

Unless that is higher than the ATO water that will not work it is not a reverse siphon.

 

[gareefer]

From the way I read it, he says the tube goes from the pump in the top off section, over the baffle dividing the top off section from the return section, and then to the bottom of the return section. Then he said the water will keep flowing from the top off section into the return section until they equal out. If that is the case, then all he has to do is make the end of the tube coming from the top off pump higher then the float switch in the return section. if the end of the tube never gets under the water line in the return section, then there is no way for the siphon to happen

Edit:

Gort;692537 wrote:

The hose comes from the pump at the bottom of the topoff water compartment , over the divider , into the mag return pump compartment and the hose now goes all the way to the bottom under water in the return compartment.

This is the problem

 

[acroholic]

Easy thing to fix.....just have the ATO tube into the Mag chamber hang down about 1" into the Mag chamber, keeping it higher than the ATO water level. When the pump stops the water stops, and no siphon. Crude non-artistic renderings below. Use a couple 90 degree barbed fittings to go over the top and into the Mag compartment and let it just hang there.
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<legend> Attached files </legend>

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class="gc-images" title="CIMG4638.jpg[/IMG] style="max-width:300px" /></a> </fieldset>

 

[grouper therapy]

GAreefer;692621 wrote: From the way I read it, he says the tube goes from the pump in the top off section, over the baffle dividing the top off section from the return section, and then to the bottom of the return section. Then he said the water will keep flowing from the top off section into the return section until they equal out. If that is the case, then all he has to do is make the end of the tube coming from the top off pump higher then the float switch in the return section. if the end of the tube never gets under the water line in the return section, then there is no way for the siphon to happen

Edit:


This is the problem

The discharge end of the hose has to be higher than the water level of the ATO reservoir to prevent a siphon. See Acroholics CAD rendering above. What you propose would prevent a reverse siphon.

 

[sts04c]

JohnIII;692542 wrote: You could put a hole in the hose right above the water line of your ato. move the hose out of the water on your return side. when the pump goes off the air whole should break the siphon.. Make sure the hole is facing the water to avoid spillage.

+1

This is the issue, with the hose being under water it causes a back siphon. Make sure the hose from ATO to Sump is out of the water and stays out, then no more problems with the back siphon.

 

[gareefer]

grouper therapy;692684 wrote: The discharge end of the hose has to be higher than the water level of the ATO reservoir to prevent a siphon. See Acroholics CAD rendering above. What you propose would prevent a reverse siphon.

I see now. Acroholics CAD drawing straightened it out for me :lol2:

 

[hammcd]

JohnIII;692542 wrote: You could put a hole in the hose right above the water line of your ato. move the hose out of the water on your return side. when the pump goes off the air whole should break the siphon.. Make sure the hole is facing the water to avoid spillage.

this works well..what i did..drilled a little hole

 

[acroholic]

GAreefer;692734 wrote: I see now. Acroholics CAD drawing straightened it out for me :lol2:

Hey, that was done using the latest software...my soft fingers.

Edit:

Hammcd;692749 wrote: this works well..what i did..drilled a little hole

That works too....like a siphon break hole in a return pipe.

Just remember, any tubing that is submerged in two liquids will want to equalize those liquids to the same level, so your 24" high ATO level and your 5" Mag/sump level will end up equal as long as there is a liquid connection between the two.

 

[kirru]

i bought a Tunze auto top off that kept having a siphon problem.. ended up drilling a hole in the cap of my drain for the display tank and that solved that problem... until the Tunze broke but that is ok since Tunze has rectified the problem.

 

[grouper therapy]

The hose can stay in the water on the return section as long as there is a place for air to enter the hose above the highest water level of the two tanks