Classic ATO failure but really weird results.

[GoodKat]

I am at a complete loss here. Last night my Innovative Marine ATO controller failed in the one position and pumped roughly half a gallon of almost fully saturated Kalk water into my ten gallon tank. I add 1.5 teaspoons of Kalk to ATO res and the ATO res in only 1 gallon.

The PH skyrocketed so I quickly did a 50% water change. However! Calcium plummeted from 430 to 390 and my ALK dropped way way down from like 7.5 or 8 to below 6 dKH.

I refill my ATO res once or twice a week, so the solution is never in there long enough to solidify.

Can some help me understand what is going on? This is the opposite of what I would expect. I am scared

 

[MnFish1]

Scared about what? Its normal - the Kalk caused precipitation. its good that you did a water change I think. Its why I don't rely on automated ATO - hoe many times do we hear this story - or the story of my ato stuck on and dumped x gallons into my tank of RODI.

 

[vetteguy53081]

Kerp sensors clean as ATO s do fail and as for kalk- monitor the unit and correct it gradually

 

[Rcpilot]

Scared about what? Its normal - the Kalk caused precipitation. its good that you did a water change I think. Its why I don't rely on automated ATO - hoe many times do we hear this story - or the story of my ato stuck on and dumped x gallons into my tank of RODI.

I built redundant shut off switches into my DIY system for this exact reason. At the time (2008) there weren't any commercially available systems with redundant shut off switches - at least none I was aware of.

 

[Aquavaj]

Likely a faulty or dirty sensor. I would clean them atleast once a month.

Assuming it's the Hydrofil one I find it silly that it doesn't have a timeout feature. If stuck on it's going to keep filling until your reservoir is dry.