Kalkwasser vs soda

[Salty2021]

Hello I'm currently dosing soda ash at night. I want to start with kalkwassser. I dose 1ml at night four times. I have mostly soft coral. So the demand not bad. I just don't want calcium to skyrocket... Just don't know if if it's a good idea.

 

[Randy Holmes-Farley Verified Community Expert]

Calcium won’t skyrocket. Limewater (kalkwasser) adds calcium and alk in Proportions very close to the relative rate that they are consumed.

 

[Salty2021]

Ok thanks it's semi proportion. I've tried it dripping it. But that's uncontrollable. Gotcha thx

 

[Randy Holmes-Farley Verified Community Expert]

Yes, corals use about 18-20 ppm of calcium for each 2.8 dKH of alkalinity. The variation comes from different amounts of magnesium in the skeleton in place of calcium. Limewater (kalkwasser) adds 20 ppm calcium for each 2.8 dKH of alk.

 

[enlighten]

If the system is mostly soft coral and/or anemones, would soda ash be a better choice over kalkwasser?

 

[Randy Holmes-Farley Verified Community Expert]

If the system is mostly soft coral and/or anemones, would soda ash be a better choice over kalkwasser?

No. Kalk is a fine alk and calcium additive for any system, and unless nitrate is rapidly accumulating, there is typically no alk consumption without calcium consumption. But the drop of both is first seen via alk dropping.