Originally Posted by rumples riot
Baking soda is the cheapest and easiest KH builder. I use a product called KH builder which comes in a bag, cost me 4 dollars and has lasted for nearly a year. The product I buy is probably baking soda, so why not try that.
Can't be baking soda if it lasts a year.
I did some calculations that will tell you how many teaspoons of baking soda to add to raise buffering capacity X amount.
X = desired raise
V = volume of water in liters
Heres the equation:
Teaspoons = V(X/183)
That is, divide the desired raise in dKH by 183. Then multiply that number by the liters of water. (1gal=3.785L)
This is just the math if anyone wants to know.
1) 0.616g Na x (1mol/22.99g) = 0.0268mol Na
2) 0.0268mol Na x (1molHCO3-/1molNa) =0.0268mol HCO3-
3) 0.0268mol HCO3- x (61.017g/1molHCO3-) x (1000mg/1g) x (2) = 3270mg HCO3-/teaspoon
4) 3270mg HCO3-/teaspoon x (1dKH/17.3mg/L) = "183dKH/teaspoon/liter"
I have used the equation and have had 100% accuracy with it. It probably won't matter much, but this equation was calculated by using Arm&Hammer baking soda (I used there ratio of .626g Na = 1/2 teaspoon, since many of use don't have scales). But pretty much all baking soda has got the same grain size so it shouldn't matter.