ATO Rookie mistake

[lagnew904]

Made my first real mistake last night. Newly installed Tunze Osmolator nano ATO has worked for the last few days without issue. ATO reservoir has been less than half full and it ran out last night and needed a fill. I took this opportunity to fill it nearly to the brim to calculate how long it would last under normal evaporation conditions.

Wake up this morning to about 2 gallons of water out of the reservoir and in the sump. Luckily no spill on the ground. Initially I thought a failure of the float switch but that would be unlikely due to it only being a week old. The Nano also has a 90 second shutoff by the microprocessor. I didn't get a picture because I was rushing out the door for work. I'm pretty sure the water was level from the sump to the ATO reservoir.

I'm thinking a siphon occurred from the reservoir to the sump. Luckily I've been running my sump level at 8'' and had just enough room to level off without flood. Anything I'm missing, does it sound like siphon to you fellas?

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[Gtinnel]

As soon as you said ato and rookie mistake I assumed siphon. If the levels are the same it's almost definitely from a siphon. When I first set up my ato I found out what 5 gallons of water looked like across my living room floor (surprising its seems like a lot when not where it's supposed to be).

I am now very observant when doing anything with plumbing not to inadvertently create a siphon I dont want.

 

[Gtinnel]

At least it easy to fix and no harm was done.

Never allow the outlet of the ato to be submerged and make sure it stays higher than the highest possible water level.

 

[lagnew904]

At least it easy to fix and no harm was done.

Never allow the outlet of the ato to be submerged and make sure it stays higher than the highest possible water level.

A submerged outlet would be back siphon from the sump into the ato correct? I don't think my outlet into the sump was submerged prior to the siphon but I may be wrong.

I think the reason I never saw it last week is because my ato reservoir was less than half full and at half full its under the sump water line. I assume a temporary solution would be leave the reservoir half full as a siphon fail safe?

 

[lagnew904]

The outlet was definitely under the water level of the reservoir but not submerged in the sump water. Ill just fill 3/4 for the time being.

 

[SPR1968]

It certainly sounds like its siphon effect from what you’ve said

it was something I was very very aware of when designing my large system with a large 425 litre ATO reservoir and I have basic systems in place to prevent it even if it’s unlikely to happen. Sort of just in case!

 

[lagnew904]

It certainly sounds like its siphon effect from what you’ve said

it was something I was very very aware of when designing my large system with a large 425 litre ATO reservoir and I have basic systems in place to prevent it even if it’s unlikely to happen. Sort of just in case!

What did you use? Air hole or a solenoid?

 

[SPR1968]

What did you use? Air hole or a solenoid?

I drilled downward pointing air holes into hoses coming out of the reservoirs in all ATO systems (I have 2 rather large tanks) to act as siphon breaks. Also into another reservoir top off system just in case

Electronics can fail so I keep to the basics on this sort of thing

 

[Gtinnel]

A submerged outlet would be back siphon from the sump into the ato correct?

If the water level in the sump was ever higher than the level in the ato then yes.

I don't think my outlet into the sump was submerged prior to the siphon but I may be wrong.

It doesn't have to be submerged to allow a siphon from the ato into the sump. It will siphon if the outlet is lower than the ato water level.

I fixed my issue with ato siphoning by attaching a 1/2" piece of pvc vertical to my already existing plumbing. I then stuck the end of my 1/4" ato tube into the top of that pvc, making sure it was cut short enough to not go very far down into the bigger pvc tube. The bigger tube directs the water into the sump and the air gap breaks siphon when the ato isn't running.

 

[Gtinnel]

I'm not home to take a picture of my air gap anti siphon (plus I have a pretty strict policy that I won't show anyone my messy diy sump...LOL) but here is a picture I found posted by another user that shows basically what I did, only my bigger pipe is pvc not vinyl tubing.

In this picture the smaller black tube would be from the ato and just needs to be smaller than the clear tubing so it's not a tight fit (air has to get in there). Then make sure the end of the black tube is high enough in the clear tube that it is higher than the highest possible ato reservoir water level.
Doing it this way doesn't rely on anything that can fail like a solenoid or check valve.

On the positive side you will probably now always take into account siphons when doing anything with plumbing.

 

[lagnew904]

I'm not home to take a picture of my air gap anti siphon (plus I have a pretty strict policy that I won't show anyone my messy diy sump...LOL) but here is a picture I found posted by another user that shows basically what I did, only my bigger pipe is pvc not vinyl tubing.

In this picture the smaller black tube would be from the ato and just needs to be smaller than the clear tubing so it's not a tight fit (air has to get in there). Then make sure the end of the black tube is high enough in the clear tube that it is higher than the highest possible ato reservoir water level.
Doing it this way doesn't rely on anything that can fail like a solenoid or check valve.

On the positive side you will probably now always take into account siphons when doing anything with plumbing.

Awesome thanks for the info. Ill get something made up this weekend. Lucky for me I'm still cycling and doing the water change today anyway. So a few hours of lowered salinity wont be any drama.

 

[Gtinnel]

Awesome thanks for the info. Ill get something made up this weekend. Lucky for me I'm still cycling and doing the water change today anyway. So a few hours of lowered salinity wont be any drama.

You don't even have to do anything to fix the salinity, just let the extra water evaporate off and you'll be back where you started. Just make sure your return pump doesn't go off because you will obviously have less space in the sump for any extra water from the display.

 

[Patientman]

Getting ready to set up an ATO and wondering (if the pump is strong enough to push the water up to the display) hang the tube above water level in one of the overflows. Fresh RO water "should" go right to the sump from there … does that sound feasible?

 

[Gtinnel]

Getting ready to set up an ATO and wondering (if the pump is strong enough to push the water up to the display) hang the tube above water level in one of the overflows. Fresh RO water "should" go right to the sump from there … does that sound feasible?

There is no reason that wouldn't work. It seems a little pointless to pump the water up that high just to have it drain right back down, but ultimately it would work that way and doesn't hurt anything.

 

[Patientman]

There is no reason that wouldn't work. It seems a little pointless to pump the water up that high just to have it drain right back down, but ultimately it would work that way and doesn't hurt anything.

Took a closer look at the pic you posted … and thinking that would be the way to go!
Thanks for sharing!

 

[Gtinnel]

Took a closer look at the pic you posted … and thinking that would be the way to go!
Thanks for sharing!

It's the easiest and safest way to do it IMO.