ATO fail : Kalwasser overdose

[psyrob]

I have had an ATO for several years that feeds my Kalkwasser from a 5 gallon jug into the sump with a float valve connected to my controller. Using the Tom's aquatic lifter pump, with no problems for all this time. Well, last night, it put two gallons of Kalkwasser at least, into my tank before I caught it. the tank looked like an evil fog had taken over, couldn't see anything and there was much distress and gnashing of teeth. I had only 5 gallons of RODI water and did a quick change, and rushed to Ultragem corals in Burbank, who, God bless them, are open until 9 pm on Friday night and bought 25 gallons of saltwater: disaster averted.

I can't figure out what went wrong. The float valve was up, not stuck, the controller had turned off power to the pump, the pump was NOT running, but a steady flow of Kalkwasser was pouring into the sump. The reservoir sits next to the sump, not above or below it, the pump is on top of the jug, about six inches above the water line in the sump. Also, the airline that feeds the Kalkwasser is also above the water line in the sump, it is not in the water. It is actually lined up with the top of the jug. I have never had this happen before and can't figure it out. Any ideas are appreciated.
Thanks

 

[Sk8r]

Not too serious. You may have set up a situation where a power out condition sets up a siphon to your ATO---if the hose from there touches the high water level in the sump. I did that once, and it really played hob with the salinity. HOWEVER, kalk is relatively harmless---the big problem is that it is fresh water and can throw your salt balance. It also arrives at ph 12, but that rapidly adjusts downward. You can help it along in a tank your size with 1 teaspoon of Schweppe's Bar Soda water. Don't overdo: it corrrects itself very rapidly.

 

[Scarface8]

I second the syphon idea, my ato reserve and sump are at the same level also, though I use a tunze ozmolator, however the outlet of the hose for ato water going into sump is much higher than both water levels

 

[tkeracer619]

Its best to use a peristaltic type pump for an auto dealing with kalkwasser.

I use a coleparmer that almost struggles to keep up with demand. Even if itg got stuck on it would take a couple days to cause an issue.

 

[Spectorman]

I use a dose pump just for this issue. I have never thought the ATO was a good idea. I am sorry for your troubles.

 

[bizacon]

I have been there as well. First tank crash was all the kalk from ATO in the tank!!

Thankful the lfs was open

 

[psyrob]

Thanks all. I don't think it was a siphon issue, as the hose is at least a couple of inches above the sump water line. Maybe the diaphram in the Tom's pump stuck open? It was strange, no power to the pump, the float valve was up and the water was still flowing. I bend the hose back into the jug so it just went back into the jug, and eventually it stopped.
I never thought about using a dose pump for top off water. Maybe that is the better way to go.