What's the best way to test water hardness

[kevikev77]

Currently using the ColorQ7 for testing my pool water. The only thing I don't like is the reagent for water calcium hardness expires in 6 months. Is there a better way to test water hardness?

 

[Jimrahbe]

Kev,

Actually, the ColorQ measures Total Hardness and not Calcium Hardness.. I know what the test says, but what they actually measure is Total Hardness.

The problem is that this measurement changes drastically depending on your local water supply.

I know this because I also have a ColorQ Pro 7.

When I want to know what my actual CH is, I use my TF-100 or now my new TF-Pro.. repeatable and accurate. Another option is the Taylor 2006C...

Thanks,

Jim R.

 

[PoolStored]

Might be a good read for you --> Test Kits Compared

 

[SecoSteve]

Kev,

Actually, the ColorQ measures Total Hardness and not Calcium Hardness.. I know what the test says, but what they actually measure is Total Hardness.

The problem is that this measurement changes drastically depending on your local water supply.

I know this because I also have a ColorQ Pro 7.

When I want to know what my actual CH is, I use my TF-100 or now my new TF-Pro.. repeatable and accurate. Another option is the Taylor 2006C...

Thanks,

Jim R.

Jim, I am using the TF-100 to test for calcium hardness. My issue is when my sample does look like it turned blue on the SmartStir, if I hold the sample up to the light in the room, it is lavender. I have to add like 10 more drops to get it to turn blue in the light off the SmartStir. I'm already at 10-11 drops on the SmartStir when I see a change. Should I just go with the first change? I've read where one could start with 5-6 drops of the final reagent, but there's no difference. Does your test look as blue off the SmartStir as it does on?

 

[Donldson]

With the TF-100 tests you add reagent until there is no further color change. So keep adding drops until it turns blue and further drops does not making it any more blue and the drop that made the final color change is the result.

 

[Jimrahbe]

Steve, @SecoSteve

It is the color change that you need to be looking for, not an exact color.. Once the water changes from to any kind of blue, add another drop, if the color changes, add another drop.. When the next drop does not make any additional color change, you are done, and you don't count the very last drop..

I did run my SmartStir and it did appear a little lavender to me, but I don't focus on the exact color, just the change...

10 or 11 drops is only about a CH of 100 which is way low for a gunite pool...

I believe that the less CH you have the less intense the color is..

Thanks,

Jim R.

 

[SecoSteve]

Steve, @SecoSteve

It is the color change that you need to be looking for, not an exact color.. Once the water changes from to any kind of blue, add another drop, if the color changes, add another drop.. When the next drop does not make any additional color change, you are done, and you don't count the very last drop..

I did run my SmartStir and it did appear a little lavender to me, but I don't focus on the exact color, just the change...

10 or 11 drops is only about a CH of 100 which is way low for a gunite pool...

I believe that the less CH you have the less intense the color is..

Thanks,

Jim R.

Thanks Jim. I'm much more confident now knowing about the color change. I'm not in front of my testing equipment now, but I thought the hardness test result was 25X each drop. I'm using 10ml pool water. I believe the TF-100 calls for 10ml pool water, 10 drops #10, 3 drops #11, and drops of #12 till it turns blue. Am I doing something wrong?

 

[mknauss]

Am I doing something wrong?

No. Jim may use the more accurate test. If you use 10 ml of water sample, each drop of R0012 to color change is 25 ppm CH.

 

[Jimrahbe]

Steve,

I don't run the CH test all that often, so I use the 25 ml sample size... Seems to me the color is "weaker" when I use the 10 ml sample.

Plus I have the TF-Pro, which comes with a bigger bottle of R-0010... So using 20 drops of R-0010 is not a big deal for me now..

Thanks,

Jim R.