Swimming Pool Acid

[chem geek]

Carl,

Is there a dry acid other than Sodium Bisulfate? The only one I've seen is 93.2% Sodium Bisulfate which actually adds about twice as much sulfate to the water for the same acid effect as sulfuric acid. 1 cup of 31.45% Muriatic acid is about equivalent in acid strength as 1 cup of 38.5% Sulfuric acid and is about equivalent in acid strength as 10.7 ounces of 93.2% Sodium Bisulfate dry acid. However, whereas 1 cup of Muriatic acid doesn't add any sulfate (it adds 1.2 ppm of chloride ion), 1 cup of Sulfuric acid adds 1.0 ppm of sulfate while 10.7 ounces of Sodium Bisulfate dry acid adds 2.1 ppm of sulfate (and 0.4 ppm sodium ion).

I incorrectly calculated the amount of sulfates from Sulfuric acid but corrected my earlier post (I only added sulfuric acid to my spreadsheet when I saw this thread and made a mistake in the sulfates calculation). There's hardly any problem at all with the 6 gallons of sulfuric acid though I agree switching to Muriatic acid is wise. As for Sodium Bisulfate, as I indicated above it adds twice as much sulfate for the same acid effect and I know there's no mistake in that (sulfuric acid is H2SO4 providing two hydrogen for each sulfate while sodium bisulfate is NaHSO4 providing one hydrogen for each sulfate).

Richard