Using Na2CO3 to calculate water volume.

[mook1178]

I have used the estimate water volume calculators on line. I am either inputting something wrong or they or wrong, but whenever I use that voluem estimate for my tank the alk addition and resulting dKH do not match the expected change.

Therefore I am going to dose some sodium carbonate and record the change in dKH and use those numbers to calculate true water volume. I am going to start the moonshiners method and want something more accurate.

I just need a double check on my math please.

Using
dmeq/l = (m*1000*2)/(106*V)
106= mol of Na2CO3
1000 to convert to mg
2 foe meq/L

I rearrange for V
V = 18.86m/meq/L

Converting meq/L to dKH using 2.8
V = 6.7m/delta dKH

Where m is mass(g) of Na2CO3

Does anybody see anything I am missing?

 

[Randy Holmes-Farley Verified Community Expert]

Why not just use an online calculator:

https://reef.diesyst.com/chemcalc/chem_calc3.html