question about using Kalkwasser for ATO

[BilboB]

Being basic, Kalkwasser in my ATO is causing my tank's pH to rise. Should I switch to water once the pH gets to 8.5, and then back to Kalkwasser when the pH is ~8.2?

 

[me & my baby]

Are you doing ATO or manual

 

[BilboB]

ATO

 

[me & my baby]

How much are you evaporating a day

 

[BilboB]

I don't know... this is more of a general question for people who use Kalkwasser in their ATO...

 

[fish_collector]

Evaporation is an important thing to know. Kalk is typically dosed at night to repl evaporated water and to largely eliminate the natural pH drop during darkness.

If you add kalk to your ATO and your pH is going very high you will need to reduce the amount of kalk you are adding, or only use your ATO at night. A tablespoon for every 5 gallons would be a good starting point.

 

[BilboB]

Oh, that's good to know. I'll use water for my ATO during the day and switch to Kalk at night. That should slow the rise in pH.

 

[Mchava]

How much kalk powder are you adding to your top off and how many gallons is it? Depending on how much you might be able to scale it down and not have to worry about switching. Its recommended to start with 1/2 tsp per gallon of RODI and adjust if needed.

 

[BilboB]

Yeah, I used 2 teaspoons with 4 gallons of water. Maybe the hose is down in the muck, though.

 

[Randy Holmes-Farley Verified Community Expert]

Rarely does kalk for all evaporated water cause pH to get too high.

Make sure you are not dosing solids and that the alkalinity is not rising too much.