White "haze" on CI piece after electrolysis

[Jonathon Davis]

I just cleaned and refilled my tank and added a new tank about two weeks ago. The first two or threes eves out of both tanks had a whitish look to the. After coming out of the electro. I assumed it was undisolved washing soda floating around in the tank. Scrubbing with stainless scrubby removed all traces.

Like Cheryl, I have quite a bit of undisolved soda in the bottom of both my tanks.

[Cheryl Watson]

I've been using regular old A&H Washing Soda.

Next trip to Home Depot, I am going to pickup the PH+.

I tried one container in the past, and it did dissolve better... so... will give it another whirl.... my freshly mixed solution above is already showing some precipitate.  (but the temperatures are swinging wildly here... still... )   [smiley=question-marks.gif]

[Jeff Friend]

As I said in Reply 19, if you see undissolved material sitting in a layer on the bottom of your tank, it isn't sodium carbonate.  And the temperature is not causing sodium carbonate to precipitate out of solution.  Please try the tests I describe above.  And you might try them with Arm & Hammer washing soda and pH+.  This is the only way we will have a chance at understanding what is going on.

[Cheryl Watson]

According to the MSDS's for:

A&H Washing Soda:  Sodium Carbonate is 85%

PH PLUS: is 99.8 -100%

So at 85 % one would wonder what the other 15% is for A&H.  MSDS lists it a water.   Interesting. Does not even list inert ingredients. 

Logic says that the 15% remaining ingredient may account for some precipitate. 

[Jeff Friend]

Since the 15 percent is listed as water, this does not explain the white precipitate unless there is something else in the A&H material that the MSDS does not mention.  For what it's worth, I looked at several specifications for industrial Na2CO3 and they generally state that the product contains less than 1 percent insoluble matter.

Sodium carbonate, like many other salts, can contain chemically bound water molecules.  When I looked at the A&H Washing Soda MSDS and saw the water content, my assumption was that the product is probably a blend of anhydrous Na2CO3 and Na2CO3 with bound water.  This is consistent with General Chemical's technical data, which states that at temperatures below 109C, the solid phase can exist at about 85 to 100 percent Na2CO3, and the balance being Na2CO3 with one water molecule.  When Na2CO3 (with or without bound water) is dissolved in water for electrolysis, the concentration of the solution is below - a lot below - the saturation point, so there would be no white precipitate.  The soda ash all goes into solution, yielding sodium ions and carbonate ions.