As long as the color continues to change, you continue counting drops. There are two things to watch out for. If you are not swirling enough you might have missed the color change changing more on an earlier drop, so slow down a little right near the end. Second, if the changes are really really small it could be an illusion or visual error, so don't worry about little tiny almost invisible color changes.

So TA 140, and CH somewhere around 160, 170 or 180.

cool, thanks. i'm using speed stir, so i'm swirling enough

Be careful with that speedstir. It makes it so eay to do the tests that you'll get in more of a hurry than you should be. Take your time and drop the drops about 1 every second or two.

Just a quick question about calcium hardness and fading endpoint.
When I test mine, the colour turns from red to purple, then to blue. Is this some kind of interference - should the colour turn from red straight to blue, or is the purple intermediate colour OK?

It should turn from red straight to blue. If it only goes purple for a drop or two it isn't a big deal, but if the purple hangs around for longer than that it can interfere with the results being correct.

Thanks. No it stays purple for at least 4 or 5 drops. Should I perform the test as per the fading endpoint instructions? Also, why is it doing this? Leftover metals from that stupid mineral cartridge I yanked out last year?

Yes, try the suggestions for dealing with a fading end point. Usually a fading end point is caused by some metal ions in the water. But other factors also effect how likely you are to see a fading end point. More stirring, such as with a speed stir, and avoid a fading end point, and a fading end point is also much less likely to appear when the CH level is low.

Hi, I just ordered more of the powder and drops for chlorine test. The powder I just received is white....the previous powder (which I've only had for about 2 months is gray with white clumps..is this powder good?

Yes, your powder is good. R-0870 powder starts out white and turns first light gray, then dark gray, and finally black as it ages.

That CYA test is sure a pain... I bought the 50 ppm standard from tftestkits, and I got 50. So I know the test is being done right. I have done a series of drain and refills to lose Calcium, so CYA went down, as expected. I dug out the old floater and bought some trichlor and started raising CYA up. And it did go up just as expected. And then it went down! I figured testing error. A week or so later, it's the same! And I added more CYA via pucks. Hmmmm..

Fast forward another week, to today. CYA is where I was originally aiming. How?

Lighting! The two low tests were done in the morning, seated, with the view tube down at arm's length. Today's test was done the way I always did it, standing, back to the sun, but very bright reflection from the patio getting full sun coming up from below. Depending on which reading I choose to believe, I was off 15 or 20.

Lesson: Be consistent! And bright light is very important for the CYA test.

Yes, when Taylor says to use strong indirect sunlight, they aren't kidding. Direct sunlight is too bright and will give you a false low CYA reading while having the light be too low will give you a false high CYA reading (though Richard, it sounds like your situation was the opposite). It probably would have been better for Taylor to provide an optional viewing device where you insert the tube and light shines in from the sides at the appropriate intensity. It would make a great companion to the SpeedStir. Of course, this starts to sound more like one of those photometer test kits and we know they aren't always so great at CYA measurements, but what I am describing is really a hybrid.

2 questions....I have the speed-stir and when I perform the chlorine test I have an awful time trying to get the magnetic bar to spin, it always gets "stuck" on one side or the other. Why is it doing this? It doesn't do it as much when I'm doing the TA and CH tests in the regular test tubes.

I'm sure it doesn't matter but can I just use a regular test tube rather than the 'CHLORINE ONLY' one?

thanks

Have you changed the battery? That the most common reason the bar doesn't spin.

I use the same vial for everything. You'll have to clean the vial more often but that's a small price to pay.

When you say you have to clean the tube more often, what exactly do you mean?
Why does the chlorine tube say "CHLORINE ONLY"? I didn't even think about the battery!!!! I have only had it since April but use it every day. Would that run the battery down that fast?

BTW, We have had sooooooo many compliments on our pool water....One person who commented on our pool has their own pool & I was able to tell her about BBB and TFP and what a great site this is. She couldn't believe I only add Bleach daily....that's it!!!!!!! I've only gone to the pool store once to get water sample tested just to compare to my numbers (they were actually kinda close) She couldn't believe how much $$$$$$$ she has been wasting and it's not getting her a sparkly pool like mine.

I have to say that this was one of the best feelings, being able to share this method with her.

The reason it's labeled 'chlorine only' is that the chlorine test tends to leave a dark residue on the vial. Bleach will clean it off easily.

The battery doesn't run down very quickly but there's no telling how long it's been in there and they don't come with the highest quality batteries anyway.

Has anyone ever tried checking/verifying the volume measurements of the round plastic vials that come with the TF-100? I "borrowed" a couple 10mL glass vials from work the other day as I figured they would be a little easier to swirl, read and clean. Just for kicks I compared the accuracy of the volume graduations. I filled TF-100 tube to the 10mL mark and then transferred the contents into one my glass vials and it was about 2mLs over the 10mL mark. I repeated this a few times with the same result. Thoughts?

BTW- These are quality, lab grade Hach test vials I used for the comparison.

When doing the CYA test, the directions I have on my TF-100 is to fill the bottle to the top of the label and then shake. Wait at least 30 seconds and shake once more. Not shake for 30 seconds. Is shaking for 30 seconds better. Thanks for all that great info. I love my kit. Filix.

Through mixing at the start and at the end are both important. In the middle, not so much. Taylor does say to mix for 30 seconds. Allowing at least 30 seconds is important, but I can't think of any reason mixing throughout is important.

Any thoughts on measuring salt, with both the strips and the K-1766, and how any of the other chems being out of balance or cold temps would affect the accuracy of the tests? In fact, I see there's a placeholder for it

I don't believe that temperature or usual chemical balance affects the salt tests. However, the Taylor K-1766 does mention the following potential interferences:


Note that 25 ppm orthophosphate is 25,000 ppb so is a level of phosphate not seen in pools. Iodide and cyanide are not normally present in pool water, but bromide may be as some is found in fill water and some may be added from sodium bromide products including algicides for treating yellow/mustard algae. Nevertheless, such bromide concentrations are usually much smaller than the chloride concentration. So in practice, the chloride tests usually measure chloride.