Question about Calcium Hardness Test in the TF-100 kit.

[rclifton]

In the directions that came with my kit it states to add 20 drops of R-0010 and then 5 drops of R-0011L and the mixture will turn red if Calcium is present. I'm using a speedstir so I know it's not a mixing issue per say but my intial results continue to come out pinkish with a purple tint. I've tried doing the test with the assumption that copper is present but again it starts out a "pinkish purple" color and not red.

So on to the question am I still looking for blue in the end? Or am I looking for any color change at all? If it's any color change, when do I stop? When the color has changed completely? Or as soon as the change starts? Sorry to be such a newb but it appears to be an issue for me as I seem to get some change in color at 40 drops (not blue) and then another change around 140 drops (again not blue). I'm trying to figure out where exactly my CH is as I have a ton of metals and sky high TA (>600) in my fill water. Getting a more accurate CH reading would allow me to use the CSI from the pool calculator a bit more accuratly so I know when it is safe to start my SWG up.

Thanks!

 

[jblizzle]

I think the important thing is to see a color change. You continue to add drops until the color stops changing. The last drop (that does not make the water change) does not count.

Have you seen these instructions with more info on all the tests?
extended-test-kit-directions-t25081.html

 

[rclifton]

I think the important thing is to see a color change. You continue to add drops until the color stops changing. The last drop (that does not make the water change) does not count.

Have you seen these instructions with more info on all the tests?
extended-test-kit-directions-t25081.html

Thanks, I had looked at that and tried one of the variations with similar results so figured they would all come out the same so I thought I would ask to make sure I wasn't doing something wrong. I just did a double alteration to the test so could someone confirm if I did it right?

I took 12.5ml of pool water mixed with 12.5ml of distilled water. I then added 5 drops of R-0012 first because of the metals present in the pool, I then added 20 drops of R-0010, and then 5 drops of R-0011L. Starting at 5 I added drops of R-0012 until the sample changed to a bluish color and stopped changing. I reached 37 drops, I multiplied that by 10 for 370 and then multiplied that by 2 to account for the half distilled water for a total CH of 740. Does that sound about right to everyone else?

Thanks

 

[JasonLion]

Yes, that sounds right. As long as you didn't see the sample turn purple (called a fading endpoint) during the test you result should be correct. If you saw purple the result might be higher than actual.

 

[Richard320]

Sounds right. Save some effort - use a 10 ml sample. With numbers as high as yours (and mine) 25 is good enough resolution.
Straight from the extended directions:

If you expect that your CH level is extremely high, you can do the test so that each drop is 25, instead of 10, to speed up the process and save on reagent usage. Use 10 ml of pool water, 10 drops of R-0010, 3 drops of R-0011L, and multiply the number of drops of R-0012 by 25 to get your CH level.

'cept I use 5 drops of R-0011L so the color is more vivid.

And since you have a speedstir, relax. When the sample turns purplish, cycle it again without adding any more R-0012. A lot of times it will go blue without any more additions.