Recommendation for PH tester

[DanF]

Now it's summer here in Australia, and I noticed that my pH-reading stabilizes a lot faster, pretty much in a few seconds.

Thanks for your analysis. I've been wondering why mine (PH60) has been taking longer recently. Perhaps it is the cooler water here in the Northern Hemisphere. However when on the phone with the company's tech support I was told that the probes are only designed to last 6-18 months, and one of the symptoms of replacement need is readings taking longer to stabilize. They also mentioned storing the device in the KCl solution when not in use to improve accuracy and maintain the probe's life.

Main advantage of the pH60 over the pH20 is in my opinion that the sensor head can get replaced when it fails, i.e. less creation of landfill.

Yes - no need to replace the entire unit. Replacement probes are available on Amazon for about USD 34.

 

[revitup]

They also mentioned storing the device in the KCl solution when not in use to improve accuracy and maintain the probe's life.

Key, I believe, if you're not doing that.

 

[DanF]

Key, I believe, if you're not doing that.

I just started using it regularly. I used it once before prior to a 4 week trip. Do you know how long the life of the KCl is? Only a one "vial" amount is provided upon purchase; wondering if I need to stock up.

 

[mgtfp]

I just started using it regularly. I used it once before prior to a 4 week trip. Do you know how long the life of the KCl is? Only a one "vial" amount is provided upon purchase; wondering if I need to stock up.

Yep, I think regular storage in KCl is crucial. The provided vial won't last long. It doesn't go off, but you loose a few drops each time you take the meter out of the solution.

I got a small 100ml bottle that will last for a while. Some pH-meters use different types of storage solution, make sure that you really buy 3-molar KCl (and don't confuse "3M" with the brand 3M and keep searching a product that doesn't exist, it just means a concentration of 3 moles per litre).

I just keep the cap filled with it the whole time and keep topping up as required. Make sure to not contaminate it by always rinsing the probe with distilled water and drying with a clean tissue.

I've been wondering why mine (PH60) has been taking longer recently. Perhaps it is the cooler water here in the Northern Hemisphere.

Yep, I suspect the main reason for the longer drift is temperature, until probe temperature and sample temperature are identical. Best to do the measurement by dipping the meter straight into the pool, so that the meter actually takes on the water temperature, and not the other way round. If the weather is too nasty to hang out for too long at the pool, I'd suggest to take a larger sample in an old ice cream tub or something like that. Just make sure that the temperature that the meter is showing when taking the reading is actually the current pool temperature. If it's off by only a little, then the error will be negligible for pool purposes, but you will still notice a drift until the probe has fully thermalized. If the temperature is still off by a lot (like a room temperature meter in near freezing water), then the error can still be significant (also depends on how far away from pH=7 you are), and the shown pH will drift quite fast.

In summer, that usually doesn't matter much - just dip, wait a few seconds, and take the reading. The reading might still change by a few 0.01, but who needs that precision for a pool. With a meter that only shows 1 digit after the ".", you most likely wouldn't notice a thing.

If you keep the pool open over winter, you need a bit more patience. Or in summer, should the water be very warm and the meter is being stored in an air conditioned environment, the drift should then be the other way round.

 

[AUSpool]

Try a different drop test comparator, they’re cheep, last forever and don’t need calibrating. Look through it with a white background behind. Manipulate the colour with the acid demand agent.

I’ve never been a fan of colourmetric tests and never able to use the Taylor pH comparator. It compares a opaque coloured solution to a solid colour on a card. It was just to hard for me to master. I switched to an old Blue Devil pH comparator that came with the old house and it was easier to use. This comparator has opaque windows that are similar to the test solution and is easier to match. I still use the Taylor reagent because its better but since my comparator uses less test solution I use one less drop.

 

[jseyfert3]

I’ve never been a fan of colourmetric tests and never able to use the Taylor pH comparator. It compares a opaque coloured solution to a solid colour on a card.

Which Taylor comparator uses a solid card? If I recall correctly, the Clear Choice Labs down there in Australia has a solid card to compare the pH, but all the Taylor comparator blocks have transparent windows that simulate looking through the actual test. For example, this is the Taylor comparator block that comes with the K-2006 (my own picture):

The OP has a TF-100 kit so that comes with a K-1000 kit for pH, which is a smaller, but similar pH comparator block so far as I can tell (I don’t own it but I’ve seen pictures).

P.S. Opaque means solid, cannot pass light. Translucent means light passes but not clear. Transparent means light passes and it’s also clear. So a wall is opaque, a frosted privacy window is translucent, a regular window is transparent. I suppose the meanings could be different in Australia though.

 

[mgtfp]

If I recall correctly, the Clear Choice Labs down there in Australia has a solid card to compare the pH

No, CCL uses a "translucent" window, too. But I'm not good at colour shade comparisons, much prefer my pH-meter. And the CCL-scale stops at 7.8 - just where my pH likes to settle. Up to 8.0 would be nice.

 

[mgtfp]

... actually, just got the CCL tube out. Haven't really used it in a while, apart from sticking my meter in. The scale is hardly translucent, probably due to being printed on a transparent adhesive label (carefully trying to get all these translucents and transparents right ).

I guess @AUSpool is onto something there, might be worth trying a different one...

 

[AUSpool]

So I guess I mean translucent but a pic tells the tail better. My Taylor comparator came with the K-2006, I cut it off and use the CYA side. Hopefully you can see what I mean from the pic. While the Taylor one may not be totally card like it is not as see through as my Blue Devil. The last I looked the one I use is similar to the MDX one sold in Homepepot and the Aussie Gold sold here in Aussie but beware the Aussie gold one must have had a production fault where three I looked at had the same colour in the 8.2 and 7.8 windows.



Edit: These don’t come like this, I’ve cut the CYA side off the Taylor and the DPD off the Blue Devil.

 

[mgtfp]

I like the look of the blue devil, might give that a try.

Thanks, @AUSpool

 

[AUSpool]

No, CCL uses a "translucent" window, too. But I'm not good at colour shade comparisons, much prefer my pH-meter. And the CCL-scale stops at 7.8 - just where my pH likes to settle. Up to 8.0 would be nice.

That’s exactly what I found, my pool wants to settle at 7.8 too. I found it difficult to tell the difference between 7.8 and 8.0 on the Taylor but already had the BD and could easily see 7.8 on that one. With the new pool I’ve found myself at 7.2 and 7.6 and had to get my acid demand reagent out to see the colour changes.

@jseyfert3, I think it was the pic of your results comparing your new meter but looking at the pics I thought I could tell the difference to the point I thought I could even see half way between. I wonder if taking a reading from a pic might be a viable option to think about? I wish you pointed out the difference between opaque, translucent and transparent a few months back, I had all sorts of drama ordering a bunch of windows for our reno.

 

[AUSpool]

I like the look of the blue devil, might give that a try.

Thanks, @AUSpool

Keep in mind that the BD comes with the DPD comparator on the other side. I cut it off so it fits in my K2006 box.

 

[mgtfp]

Keep in mind that the BD comes with the DPD comparator on the other side. I cut it off so it fits in my K2006 box.

Good idea.

And which reagent do you use, R-0014 or R-0004 (which is the one that CCL uses)?

 

[jseyfert3]

@jseyfert3, I think it was the pic of your results comparing your new meter but looking at the pics I thought I could tell the difference to the point I thought I could even see half way between. I wonder if taking a reading from a pic might be a viable option to think about?

Perhaps? That pic was taken with an iPhone 12 Pro, iPhones tend to ratchet up the colors a bit. I think I agree the picture may be easier to tell than in real life. I usually struggle in the upper end of the range myself. That said I now have the Apera PH60, no more struggle, no limit to 10 ppm FC, and no limit on measuring above or below the range of the test block.

I wish you pointed out the difference between opaque, translucent and transparent a few months back, I had all sorts of drama ordering a bunch of windows for our reno.

Uh oh, sounds like a story there!

 

[AUSpool]

Good idea.

And which reagent do you use, R-0014 or R-0004 (which is the one that CCL uses)?

I use the R-0004, its more concentrated then the R-0014 and made for the larger Taylor 2000 series comparator. The R-0004 is the one that CCL uses. The Taylor comparator as supplied with the K-2006 uses a 45ml sample while my Blue Devil uses a 35ml sample, so I only use 4 props per test. Having said that the colour is dictated by the pH, not the amount of reagent. An extra drop would only increase the intensity and not the colour.

 

[duraleigh]

Sorry, but I am a good natured "wet blanket" on what y'all are going through. The Taylor K-1000 comparator Phenol Red block (found in the K-2006C and TF-100) is perfectly adequate for ANY measurement of pH in ANY pool. It simply works.

Failure to recognize that it works falls on the operator "needing" it to fail ( I have no idea why) or a lack of understanding of the precision necessary to operate your pool successfully.

I have a PH20, he has the PH60. PH60 is accurate to within +/-0.01, PH20 is +/-0.1. I guess the 0.01 takes longer.

Sorry to pick on you as an example, rmontgomery, but that is just crazy to be interested in that resolution......it makes NO DIFFERENCE TO YOUR POOL or your pool maintenance by ANY stretch of the imagination....ANY stretch. A resolution of .2 begins to make some difference in your chemistry responses but not by much.

I really don't intend for this to be condescend but members need to know for a fact that the Phenol Red pH comparator test works like a charm, has worked like a charm for decades and will continue to adequately measure your pH decades more into the future. If you don't believe that, you are making the chemistry-selling folks very happy and there is absolutely nothing wrong with that but it is unnecessary

 

[AUSpool]

Why do I suddenly feel like a naughty boy who’s been told to stand in the corner?

I don’t think anyone in this thread has said there is anything wrong with the Taylor comparator, there is however, a bunch of users who have reported problems with colour differentiation, myself included. And so they ask and want to talk about an alternative that will make their pool care easier. To me, making pool care easier is one of the founding ideology’s of TFP. So what’s the problem, there are some pool owners that will at some stage use a cheap pH meter so why not engage in sensible dialogue in the best use practices?

I love my Taylor kit and no one is saying that their comparator doesn’t work, but could they improve on perfection. Most definitely. But they wont if they don’t know they could. I would have persisted with, and probably would have mastered or lived with the K2006 comparator if I hadn’t had the other one just sitting there.

TFP has adopted a pH of 7.6 to 7.8 as the ideal target and a pH of 8.0 as the top end of the range. The high limit of the Taylor comparator is 8.0 which works but 8.2 would be better.

And for everyone using a cheap pH meter the second decimal point is only used to round up or down. Your kidding yourself if you think you can get to +/_ 0.01 pH unit.

 

[duraleigh]

I knew it would be misconstrued. It's a 14 year old problem with the forum. You folks (and I read ALL your posts) are pool nerds. The nuances you write about are right in your wheelhouse.

The issue is for the fairly recent newbies who understandably take away from this thread that perhaps the phenol red pH test is troublesome and unreliable. and that's just not the case. With their limited knowledge, they come away from this with misleading information. I understand no one in this thread is "teaching" but they are "learning"

 

[setsailsoon]

Just for clarification, the phenol red pH test works great for my wife and everybody I know except me. I'm the weird one and I just wish I could use the drop test like everybody else. I wouldn't recommend a digital tester for most people... just not worth the trouble.

Chris

PS All this said, I'm definitely a pool nerd too!

 

[mgtfp]

Let's start with a confession: I am a pool nerd.

I understand that the Taylor phenol red test is a reliable, easy to use pH test with a resolution that is absolutely sufficient for pool maintenance.

As long as one is able to differentiate the different shades of orange/red. For the vast majority of people, that seems to be the case, no need to reinvent the wheel or pay unnecessary money, just go with it. TFP's recommend and preferred option, no discussion about that.

But there seem to be at least a few around, that are struggling with that. And I was glad to get some reassurance on this forum that I am not the only one. And to learn about alternatives, and the limitations and downsides of these alternatives, and not just being told that there is something wrong with me, and I have to practice harder to be able to use the phenol test.

I think it is important for those using pH-meters, to understand that just because it is showing a number on a digital display, that this number isn't necessarily correct. It needs regular calibration. You have to understand that the integrated temperature compensation can only work if the integrated thermometer has sufficiently thermalized to the sample temperature. And when a continued slow drift of the reading should be ignored, and when the error can be in the range of 0.2 (as in the case of sticking a meter that's been stored in a heated room in cold pool water in winter).

And I am very grateful for @AUSpool's contributions pointing out the influence of translucency, that there are other options to using a pH-meter when struggling with colour shades. And for his and @jseyfert3's comments that it seems to be easier to differentiate between shades on photos than in real life - I was thinking the same, and that gives me hope that a comparator that mimics the translucency of real samples might do the trick for me.

Part of the discussion was also about the Clear Choice Labs comparator that the folks from Down Under are predominantly using, with a scale only up to 7.8 - which is a clear downside when pH settles in the 7.6 - 7.8 range.