PH Testing - R-0004 (40mL) vs R-0014 (9mL) - Why Difference in Sample sizes?

[Scoop]

I've been thinking of getting one of the larger Taylor Comparator Blocks (9058, for example) for testing pH.

Why does Taylor provide 2 sample sizes for pH tests? The R-0014 test is usually referred to as the "residential" test and the R-0004 test is referred to as the "pool service/professional" test.

Does the larger sample size test provide any advantage of accuracy vs the smaller size?

 

[ewkearns]

Most people feel that the larger pH tube in the 2000 series comparator is easier to read, yet uses the same amount of reagent (5 drops). It, also, comes with the benefit of a CYA tube that drastically cuts the amount of CYA Reagent (R-0013) needed per test. The 2000 series comparator only reads to 30 ppm, but I've never seen that as a problem.

 

[Scoop]

Thanks for the info

Regarding the CYA Test with the 9058 Comparator Block: Does it work the same way as with the Taylor 9193 Tube and the 9191 Mixing Bottle, using 7mL R-0013 reagent?

How does the 9058 Comparator Block reduce the amount of R-0013 reagent use?

 

[ewkearns]

How does the 9058 Comparator Block reduce the amount of R-0013 reagent use?

The 9191 mixing bottle uses 7 ml of R-0013 reagent. If you are currently using that bottle, you won't see any savings with the 2000 series comparator. Both the 2000 series comparator and the 9193 tube use the 7/14 ml sample. The 9193 tube reads down to 20 ppm.

 

[JoyfulNoise]

I've been thinking of getting one of the larger Taylor Comparator Blocks (9058, for example) for testing pH.

Why does Taylor provide 2 sample sizes for pH tests? The R-0014 test is usually referred to as the "residential" test and the R-0004 test is referred to as the "pool service/professional" test.

Does the larger sample size test provide any advantage of accuracy vs the smaller size?

The R-0004 and R-0014 use the same chemistry (Phenol red) but are differ in their concentrations. The R-0014 is used with the residential or midget comparator block and that block has the following pH scale - 6.8, 7.2, 7.5, 7.8 & 8.2. The 9058 block uses the R-0004 reagent and it has the following gradation - 7.0, 7.2, 7.4, 7.6, 7.8, 8.0. So the midget block will let you test out further into the extremes (6.8 and 8.2) but the 9058 block has better solution in the mid-range values.

I have both blocks and I use them both. I only have acid/base demand reagents (R-0005 and R-0006) for the larger block so I will sometimes use that to confirm that my color perception is where I think it is.

As for the CYA test cell, the 9058 block is more than adequate for the task. I really see no need for being able to measure CYA down at 20ppm AND 20ppm is really the limit of the test. The melamine cyanurate complex is soluble in water up to 20ppm which means anything less than that will not cloud the water. The only pools that need to be concerned about low levels of CYA are indoor pools, so unless you have an indoor pool, the 9058 tube is the way to go.

 

[Scoop]

Thanks for the info. I've been using the 9058 block for pH and CYA for a couple of weeks. It's easier for me to see the pH range with the 9058 block.

CYA, for me, it's close between the vial and the 9058 block as to which one is easier to see the disappearing dot. The 9058 block seems to be best for my eyes with this test.

 

[ewkearns]

Far more thought and design has gone into the Taylor testing paraphernalia and their interaction with the reagents and samples than people realize.