Walmart Chemicals?

[lagreca]

I remember reading somewhere that buying spa chemicals at Walmart was NOT a good idea. I'm wondering which chemicals this refers to and why?

A friend gave me some Muriatic acid, which I have been using to lower pH. At some point I'm going to run out and will need a way to lower pH. I'm wondering if the hth Spa pH Decreaser they sell at Walmart is ok to use? It claims to be 91% Sodium Bisulfate, with 9% inert ingredients. Or would I be better off finding more Muriatic acid?

I bought a hth 3 way test kits at Walmart today. I have a Taylor K-2006, but I wanted a cheap and QUICK way to test the chlorine and pH. I've tested it against my Taylor and so far it seems like it will work...

[lagreca]

Does anyone have a response or opinion?

[chem geek]

If you want to continue to use Muriatic Acid you can get that at most hardware stores. The half-strength version (15% hydrochloric acid) fumes less than the full-strength version (31.45% hydrochloric acid). The dry acid you refer to (usually 93.2% sodium bisulfate) is fine to use and the Spa pH Decreaser sounds OK to use.

Possibly the "bad" chemicals from Walmart would be some imported from China that were not as advertised. I've heard of problems with Cyanuric Acid (CYA) purity, for example. You can get many of the chemicals you need from the grocery or hardware stores. In addition to Muriatic Acid, not the following equivalents:

pH Up (sodium carbonate) is identical to Arm & Hammer Super Washing Soda (careful: NOT the laundry detergent) and to raise the pH with half the rise in TA you can use 20 Mule Team Borax.

Alkalinity Up (sodium bicarbonate aka sodium hydrogen carbonate) is identical to Arm & Hammer Baking Soda

Calcium Hardness Increaser is equivalent to Peladow or Dowflake.