Tunze ATO siphoning water back into sump

[m0nkie]

Anyone have this problem and have a good fix?

My water reservoir sits at the same level as the sump. Whenever the ATO pump stops, the water keeps draining from the reservoir to sump, causing the ATO alarm to go off.

How can I prevent this siphon? Are my only choices:

1) a check valve on 1/4" ATO tube
2) drill a small hole on the 1/4" tube and place it inside reservoir, above water level.

both options doesn't seem very safe to me. check valves fail. Drilling a hole is alright but if that tube ever moves and fall into water, my sump might overflow again.

 

[rvitko]

This is siphon situation 3 in the chart attached, the best solution is to put gravity on your side, our preferred and generally best install is as shown in siphon situation 1, only avoiding the hose contacting the water surface. Sensors remain in the sump, top off hose goes to the tank or overflow box. A check valve will not work, you cannot use a check valve to stop the flow of water in the direction it would normally travel, while it may stop the flow only due to the added resistance, it is not a good solution. The pump has a fair amount of pressure and you would be amazed by how far the water can shoot from even the smallest hole, I don't suspect that will be a good solution either. As shown in the graphic, the solution is that point A always be above point B.

 

[m0nkie]

Ahh so the inlet hose goes to DT. Thank you good sir

 

[m0nkie]

made a minor adjustment. but problem solved! thank you

 

[James77]

Just a suggestion...I would somehow attach the black tube to the PVC. While it is unlikely, I can picture that slipping out....it would for me

Even just ziptie it to the PVC 6-8 inches down so the weight of the tube is not pulling on itself.

 

[reelredfish]

I have the same problem little different setup but the same problem. As of right now I have a valve at the ATO tank.

My RODI storage tank is in the garage my lines run through the attic and down to the ATo tank.

Still looking for a solution that will work for me as for gravity is not gonna work for me.

 

[rvitko]

The only possibility will be the air gap shown by monkie, their is no other way to stop the siphon besides a shorter reservoir or higher hose terminus.

 

[hernandez101]

Add a check valve to the lines BRS sells them

 

[rvitko]

A check valve only works for a back siphon, it cannot reliably stop water flow in the direction it is intended to travel.

 

[reelredfish]

Correct i am not dealing with a back siphon here.

 

[reelredfish]

anyone?

 

[Rwinfrey]

I really dont understand ......keep your fill tube out of the water and you wont have a problem . I mean tunze even includes the bracket to do this........

 

[reelredfish]

Its not a back siphone. Tube is not in the water at the tank side only in the water at the rodi storage tank side.

 

[reelredfish]

Guess no one has an answer here. Only thing I can think of is to use a different type of pump in the garage to push the water to the ATO tank in the fish room. Like a doser pump maybe that would prevent the free flow after the pump has shut off.

 

[rvitko]

The best solution is what m0nkie posted, an air gap. The only pumps that will not siphon are peristaltic and flapper pumps, both of which are very slow and this will be an issue given the 10 minute safety shut off. They are also fairly expensive and will require the switched socket adapter. Even than it is not impossible for these pumps to fail and siphon, for example a broken roller or flapper. Their is no other way I know of besides this.

 

[reelredfish]

Once again an air gap would not do anything.

Its not a back siphon.

 

[rvitko]

The airgap will stop a forward siphon if you build it right, you need to have the pipe that the hose attaches to at the same height as the water level in the reservoir, you are pumping into the pipe and the pipe is essentially a gutter to the sump, this will stop a forward siphon.

 

[reelredfish]

Sorry Roger but i dont see how that would work. I have an air gap already at the ATO tank. If i put an air gap in the RODI storage tank i would be pumping air and not RODI water so the system would not function at all.

Also just spoke to Ryan at BRS and be had me email you directly about the water valve to see if it can be used.

 

[reelredfish]

Also a little searching and I found these which I am pretty sure will do the job.

http://www.electricsolenoidvalves.com/1-4-120v-ac-electric-plastic-solenoid-valve/

May place one at each end that way there is a safety factor. In case one was to stop working the other one would still do the job.

 

[rvitko]

With the switched socket, that could work (they are 120V), but if you excuse my drawing skills, this would work for much less money and be far more trouble free-