Help - ATO switch - dumped water on floor


New member
Somehow I think my Auto Top Off switch got stuck and too much water was pumped into my tank. The aquarium overflowed about 5 gallons onto the kitchen floor.

I think a snail might have been the culprit. I have a JBJ ATO and the float has plastic shields on the sides but not on the corners.

What can I do to prevent this in the future?

Please help.


Premium Member
<a href=showthread.php?s=&postid=14790132#post14790132 target=_blank>Originally posted</a> by jimmyd01
I have the same one ^^^^
And put it on a digital timer thats on for only a minute several times a day.

Great idea. That would be a third line of safety. Pretty certain your covered after that. However, my tank has a frustrating way of overcoming all the little safety features I build in. It's like it's trying to test my integrity and prove that no matter what I do for preventative measures, it can overcome them. It's usually such random stuff that goes wrong a person could never have predicted it. Who would have thought 12 snails could pile into two different overflows in one day and flood the place???? (I cleaned the overflows the day before and know they were empty)

Gotta love reefing. It keeps me on my toes!



New member
I don't run the JBJ but form what I've read there are a few ways to hook it up.

I would change it so both sensors are in-sump & the second is used as a fail-safe for the 1st. If you can use an aqualifter pump, it can run dry without damaging the pump.


New member
I put both switches in the display tank. One for minimum and one for maximum level. I am also looking into snail shields and may make them out of old prescription bottles.


On Yer left!
Premium Member
I dont like that setup for exactly the reason you posted about. There is no fail safe. A better setup is to have one switch for high/low level sensor topoff, and the other as a backup high level override. You can set up a JBJ to do this, but for some reason, they dont document it.