Using Kalk to raise Calcium/Alk in newly mixed seawater

[brandonberry]

I just had an interesting yet disappointing thing happen. I wanted to boost my calcium/alk in the seawater I was mixing, so I figured I'd add about a teaspoon of Kalk to the 5 gallons of DI water before mixing in the salt. After I mixed the salt in and let it set overnight, I noticed that I had quite a bit of precipitation, so I figured that the kalk had just preciptated back out. I expected the calcium/alk to be about what it would have been if I had not added the kalk. Surprisingly, both my calcium and alk were severely low. Is this due to not enough magnesium or could it be due to the increased pH of the kalkwater causing rapid calcium carbonate formation? Is there any way to reverse this process by adding CO2, vinegar, etc?

 

[randy holmes-farley]

You can't add that much lime. You pushed the pH very high, causing precipitation of calcium carbonate and maybe magnesium carbonate and magnesium hydroxide, dropping calcium, alkalinity and possibly magnesium. If you want to make corrections, there are better ways than limewater. This article will help:


Solving Calcium and Alkalinity Problems http://www.advancedaquarist.com/issues/nov2002/chem.htm