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Calcium - Zero?


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So, previously I had been testing for TH (Total Hardness) but after reading a lot here I am finding it not to be the same as Calcium Hardness.

I buy the recommended Taylor Kit ... which has the chemicals to test for CH (Calcium Hardness).

Upon doing so, it says to add one thing to get red (indicating calcium present) then another to turn it to blue (10X drops is the PPM).

So, the first go at it and it turns a slight pink .. but after like 1 drop it goes clear, never to blue.

What gives?

I assume I have Zero Calcium or too little to detect?

HELP

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So you first added 20 drops of R-0010 calcium buffer (there's no color at this point and the purpose of this is to precipitate out any magnesium as magnesium hydroxide so that you next measure calcium hardness instead of total hardness), then you added 5 drops of R-0011L indicator dye and it only turned slightly pink and not red (or sometimes it looks a little purple)? What color is your indicator dye? According to Recognizing a Compromised Reagent:

R-0011L Calcium

Hardness Indicator

This solution should be a deep blue color. Any other color is an indication of replacement.

After that you add R-0012 where each drop is 10 ppm and it should turn from red to a blue color.

It should not turn clear. If you had no calcium hardness at all, then you would get blue when you added the indicator dye.

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You can also use a 10 ml sample, add 10 drops of R-0010 and 3 drops of R-0011 indicator. Then every drop of R-0012 titrant would be equivalent to 25 ppm CH. The color change will happen faster and will be easier to see.

When you do this test keep adding drops until one more drop produces no additional color change and then don't count that last drop.

Also, the color change is more of a hot pink to sky blue color with a purple intermediate.

http://www.taylortechnologies.com/ChemistryTopicsCM.ASP?ContentID=35

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