Tunze Osmolator 3155 overfilled tank by 23 gallons

[MikeIkerson]

Brand new tunze osmolator 3155 put on a brand new tank last night. I set the sensors up according to the directions and tested it by raising the sensors half a inch above the waterline and let it fill. It stopped before the float sensor was activated. This was last night. I woke up this morning to the alarm going off and my sump overfilled by 23 gallons. Both sensors for the tunze were 3 inches underwater and my 29gal ATO was almost drained. I unplugged the ATO and went to work, came home and drained the excess water. Luckily my sump is large and could handle the extra water but I may not be so lucky next time. Any ideas on how this could have happened? No bubbles on the sensors and the float sensor was not stuck and definitely floating. I’m just stumped on how one of the best ATO can overfill a tank by 23 gallons? Return pump has been set at a fixed speed the entire time. Any help is appreciated.

 

[mtdaly85]

My only guess is that the end of the tube that fills your tank was below the water level of your ATO: probably created a siphon that slow dripped overnight.

 

[MikeIkerson]

My only guess is that the end of the tube that fills your tank was below the water level of your ATO: probably created a siphon that slow dripped overnight.

Thank you. You are probably right, the tube is below the ATO water line. Not sure how I’m going to fix this now.

 

[mattzang]

the siphon thing is what happened to me with my 3155, kinda absurd it doesn't come with a siphon break

i have the innovative marine 15g ato container so it's quite a bit taller than my sump

 

[MikeIkerson]

the siphon thing is what happened to me with my 3155, kinda absurd it doesn't come with a siphon break

i have the innovative marine 15g ato container so it's quite a bit taller than my sump

Solved in minutes. Thanks!! How did you end up fixing yours and adding a siphon break?

 

[Reef.]

Solved in minutes. Thanks!! How did you end up fixing yours and adding a siphon break?

a siphon break has its drawbacks too, it’s just a small valve, you cut the tube and then push each end of the tube onto the valve, thing is they leak so you have to have it over a container.

best just to have it setup not to be able to siphon...the manual has loads of examples of how to do this.

 

[mattzang]

Solved in minutes. Thanks!! How did you end up fixing yours and adding a siphon break?

i didn't know what the issue was immediately and i was leaving for about 10 days the day after, so i put in my duetto ato and am just trying to sell the 3155. easy fix, but i realized i had no real reason to ditch the duetto, it has worked great for me

 

[jda]

Add the water to the display, not the sump. Easy fix and safe.

 

[TX_Punisher]

Yep. Plumb topoff to your overflow. Exactly what I did. Problem solved.

 

[trmiv]

This is what I do. A piece of pvc tie wrapped to one of my overflow pipes. The top of that pvc is about 4” taller than my reservoir. The ato line end is just inside the top of the pvc, so it’s above the reservoir, but is able to just run down the pvc so it doesn’t splash or make a ton of noise.