Chemical equation for 2 part

[takayan]

I have basic question about 2 part.
For 2 part method, Na‚g‚b‚n‚R for KH and CaCl2 for Ca are used.
I can understand why Na‚g‚b‚n‚R and CaCl2 increase KH and Ca level. Howver, if you continue to use Na‚g‚b‚n‚R and CaCl2 maintain these levels, do not we have a problem which cause low KH and Ca level?
For example, when we use Na‚g‚b‚n‚R to increase KH, isn't it lower/not to increase the Ca level? Because Ca ion are more affinity than Na ion. Therefore, Na ion will take out seats from Ca ion. (CaCO3 is precipitation.)
A similar reaction will be taking place for adding CaCl2. HCO3 ion is more affinity than Cl ion. Cl ion will taka out seats from HCO3 ion.
I know many people are maintaining their KH and Ca level high, but I would like to know the chemical reaction of how 2part can maintain high KH and Ca level.

[Randy Holmes-Farley]

I do not know what Na‚g‚b‚n‚R is, but I identify everything in the recipe and what is left behind here. There is no logical problem with the method that prevents attaining desired levels of calcium or alkalinity. Salinity does very slowly rise, and should be measured and reduced once in a while, if necessary.

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System
http://reefkeeping.com/issues/2006-02/rhf/index.php

[Randy Holmes-Farley]

I discuss the detailed chemistry behind all of the various methods of supplementing calcium and alkalinity in this article:

How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

[takayan]

Thank you very much, Dr. Randy Holmes-Farley.
I still need to study your article. If I have some questions, please help me to understand the chemical reaction of 2-part.

[Randy Holmes-Farley]

I will be happy to help if you have additional questions.