Alkalinity, pH, and Soda

Because of the chemistry of it doing it's job in the salt water, Baking Soda solution will temporarily decrease pH by a point or two for an hour or two. It's not a problem though. (Good pH is very dependent on having good Alkalinity, water flow and gas exchange at the water surface. In a reef aquarium, a chemical additive should never be used to adjust pH.)

Soda Ash solution will temporarily increase pH by a couple points for an hour or two.

Combining the two in a 4:1 ratio balances the effect of each to eliminate the temporary pH effect.

One thing I like about using Soda Ash in the solution is a quick clouding effect that dissipates in a few seconds. That's a reaction with Mg in the water that quickly dissolves back into solution. This is not to be confused with the "snowing effect" which can be an indication of too high Alk/Ca levels in the tank. This snowing effect can also occur if the Alk is added too fast or if the Alk and Ca solutions are added too close together.

I hope this wasn't too much information.


Edited by Mark Peterson - September 19 2010 at 11:29pm

Where can you buy the soda ash?

In the grocery stores it's called Washing Soda, but the packages I've seen are so large that, especially when it's only 1 part washing soda to 4 parts baking soda, I choose to bake a single package of baking soda.

jcom wrote: BobC63 wrote: Where can you buy the soda ash?   I know you can bake your own, but I'd also like to be able to just go to the store and pick some up.       Ace Hardware has Arm & Hammer Washing Soda for $3.79, but Wal Mart has the same sized box of Arm & Hammer Baking Soda for $1.00    So, if you have cookie sheets and an oven, you can get almost 4 for the price of 1 by going the Wal-Mart route.