ATO disaster.

[Ckgrey007]

I have a small reef tank, doing very good. Loads of fun stuff, beings the display tank is only 20 gallons or so and the sump about 10 it constantly needs to be topped off. I installed a ATO everything worked fine. I added some fish last night it kicked in for the first time in person worked perfect (tunze nano ato) this
Morning I woke up I heard dripping didn’t sound right went into front room and FLOOD! The ato reservoir was full and overflowed and pretty much sucked OUT a few gallons until the last chamber in the sump was dry and the return was just blowing air, any idea how this could have happened? Only thing I can think of is the hose that dispenses the RODI water to the display tank was underwater. Maybe too much “lead” and it created a siphon and started to suck water back into the res after it topped off.

 

[davescj]

Do you have a float valve that tells the ATO to add water? Maybe it malfunctioned?

 

[Silver14SS]

Yep, sounds like a siphon. Did you install it? If so, should be pretty easy for you to see if the discharge of the ATO hose is underwater or not.

 

[Ckgrey007]

Yep, sounds like a siphon. Did you install it? If so, should be pretty easy for you to see if the discharge of the ATO hose is underwater or not.

Yep. It was

 

[Viking_Reefing]

Yeah, sounds like a siphon. Never leave the tube under the water.

 

[Ckgrey007]

Positive note everyone is okay, I was able to just add the water from the res back and got the water level to where it can run until I can figure it all out.

 

[Michael Curtis]

The other posable reason adding to that is if you had your ato reservoir lower than you sump it made it into a reverse gravity drop from one to the other

 

[Ckgrey007]

Funny in alll the videos and reviews etc this was never mentioned but it must be common sense in this hobby and I didn’t know better. Sure do now.

 

[Silver14SS]

The other posable reason adding to that is if you had your ato reservoir lower than you sump it made it into a reverse gravity drop from one to the other

AKA a siphon . If the ATO reservoir is below the sump and the discharge of the ATO tube is underwater, it can pull water back to the reservoir when the pump is off. If the discharge is not submerged, worst that can happen is the water in the tube goes back into the reservoir.

Funny in alll the videos and reviews etc this was never mentioned but it must be common sense in this hobby and I didn’t know better. Sure do now.

Water flows downhill, siphon breaks are always a good idea. Experience is a valuable teacher, sounds like you'll only make this mistake once.

 

[Michael Curtis]

watet will always flow to the lowest point so like when you syphon water out the tank its the vacuum caused by the water dropping below the tubes inlet level in the tank that pulls the water in from the tank.

 

[Michael Curtis]

AKA a siphon . If the ATO reservoir is below the sump and the discharge of the ATO tube is underwater, it will pull water back to the reservoir when the pump is off. If the discharge is not submerged, worst that can happen is the water in the tube goes back into the reservoir.

Yep just putting it in basic terms as to why it would happen

In mine there's a syphon brake just before the pipe go's over into the return so as to reduce the risk but I can assume if the syphon was strong enough its wouldn't be much help.

 

[Reef.]

Funny in alll the videos and reviews etc this was never mentioned but it must be common sense in this hobby and I didn’t know better. Sure do now.

TBF it does say in the setup instructions you get with the ato.

 

[Saltyreef]

I have one of these inline that was included with my duetto ato. It sits right above the full waterline on my reservoir.

Will make your ATO experience much better

Smart ATO Replacement Siphon Breaker

Smart ATO Replacement Siphon Breaker

www.marineandreef.com

 

[Saltyreef]

Yep just putting it in basic terms as to why it would happen

In mine there's a syphon brake just before the pipe go's over into the return so as to reduce the risk but I can assume if the syphon was strong enough its wouldn't be much help.

A small pinhole oriface should suffice. Just gotta make sure its not clogged up with crud.

 

[Silver14SS]

TBF it does say in the setup instructions you get with the ato.

Good call, when all else fails, read the manual https://www.tunze.com/fileadmin/gebrauchsanleitungen/x3152.8888.pdf

 

[Paulandreti]

Happened to me too durin a small power outage, the ATO just reboot and the pump sucked about 10 gallons of water, just make sure the hose is above water level and no worries.

regards,

Paulandreti

 

[Saltyreef]

Wa

Good call, when all else fails, read the manual https://www.tunze.com/fileadmin/gebrauchsanleitungen/x3152.8888.pdf

Water can still easily overfill the retuen chamber even when the tube is above the water line if the return chamber level is lower than the ATO res level without a siphon break.
I nearly threw away my ATO until i found the siphon break was clogged with kalk.
It equalized everytime i would fill the ATO container to the top cause the pump created a siphon even after it turned off...


ATO tube was always above water line

 

[BullyBee]

Atleast everything is ok. Forget about what the manual did or didn’t say. You know now. The fish are ok, corals are ok.

 

[rkpetersen]

Gotta have that siphon break esp if the output is underwater. As noted, most ATO systems come with one. Or you can use an add-on unit with built in siphon break, like this one I installed on my nano.

Auqa Gadget Titanium HydroFill ATO Controller (OPEN BOX)

Innovative Marine is always offering the latest in aquarium technology. The new Hydrofill titanium ATO controller utilizes conductivity sensors making it a perfect auto top off controller for either fresh or saltwater aquariums. Hauling buckets, and daily refilling are now a thing of the past...

www.marinedepot.com

 

[Saltyreef]

The only way you would never need a siphon break is if your return chamber water level was higher than the ATO water level, or, if the output of your hose is higher than your ATO.

My output is at the level where without a siphon break it dispenses about 1-2 gallons of water after pump shuts off. Hose is above water level.

Otherwise, siphon break it is.