# Anyone know of a high range pH test kit?



## Guest (Aug 15, 2008)

I'm looking for a high range pH test kit that goes at least up to 9. Anyone know of any? I'm NOT looking for one of those digital ones though (too expensive).

Currently I use a 100test Mardel Labs 5-in-1 test kit which measures pH up to 8.8.

~Ed


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## blairo1 (May 7, 2006)

http://www.seapets.co.uk/product-detail ... y/753.html

It's the one I _used_ to use. I use a digi one now though, a lot quicker, a lot more accurate and not that expensive really - you can pick them up for pretty cheap and as long as you calibrate it regularly it'll do the trick - mine cost me something like $30, I just calibrate it once a week - don't be fooled into chucking the calib solution after use either - you can re-use it a load of times as long as you keep the container and pH stick spotless, there's no worry of contamination. Worth replacing once in a while but it's cheap (3-4$). It cost me the price of two pH test kits to get my digi probe and calibration solution, but I've already used it a couple of hundred times, easily.

My digi probes range is from 0-14 and is accurate to a tenth of a degree (+/- 0.1). I would like a more expensive one, but this is incredibly accurate and it only strays about .1-.2 within 1-2 weeks if I don't calibrate it. Can't argue with that unless you're really strapped for cash!

The above test kit always confirms what my digi probe reads, so it's good enough in my eyes.

Alternately:
http://www.indigo.com/Test-Strips/gph-t ... -7-10.html
http://www.indigo.com/Test-Strips/gph-t ... -1-14.html


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## Guest (Aug 16, 2008)

blairo1 said:


> http://www.seapets.co.uk/product-details/stkcode/662550/category/753.html
> 
> It's the one I _used_ to use. I use a digi one now though, a lot quicker, a lot more accurate and not that expensive really - you can pick them up for pretty cheap and as long as you calibrate it regularly it'll do the trick - mine cost me something like $30, I just calibrate it once a week - don't be fooled into chucking the calib solution after use either - you can re-use it a load of times as long as you keep the container and pH stick spotless, there's no worry of contamination. Worth replacing once in a while but it's cheap (3-4$). It cost me the price of two pH test kits to get my digi probe and calibration solution, but I've already used it a couple of hundred times, easily.
> 
> ...


Is that $30 you listed in british pounds, euros, or US dollars? The places I checked here in the US have them for sale at like $80usd which is too much, at least right now it is for me.


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## blairo1 (May 7, 2006)

That's Â£15 I spent, maybe Â£20 (it was a while back). So I put a rough $30-$40 mark down.

Look at the ones on e-bay from hong kong..... Cheap, plastic, ****, but with regular calibration they're just as accurate, you just need to be extra sensitive with them because a hard knock can send it way out.

Same thing but someone has obviously bought a load in your country:

http://cgi.ebay.com/Digital-pH-Meter-Aq ... 286.c0.m14

It might not come up, in which case it's the very first one if you search for, digital ph meter.

As for the calibration solution, just search - ph calibration solution. You'll want one for pH 7 and or 10 (don't get the little sachets get the bottles). You want calibration solution as close to the general range that you will be testing - ie it'd be useless using my 4.0 calibration solution when all my tanks are pH 8+ because over that range inaccuracy starts increasing.

:thumb:


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## Guest (Aug 17, 2008)

I keep tanks between my regular tap water which is 6 and after using buffer 8.4. What calibration solutions should I use?

Or would I have to just recalibrate it when I want to test what I know is a lower pH?


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## blairo1 (May 7, 2006)

> I keep tanks between my regular tap water which is 6 and after using buffer 8.4


Yup, you and me both bud.

I'd use a pH 7.0 calibration solution - that will be as accurate as you can get to cover your 6-8.4 range. It's not too essential but it just ensures better accuracy - eg. I use a 4.0 solution to calibrate occasionally and I've tested it in my Tang tank - reads 8.3, calibrate it with 7.0 solution, reads just the same.

7.0 calibration solution would cover you accurately through the range that general fish could comfortably live in. It really isn't necessary to get the 4.0 or 9.0 solution unless you're dealing in extremes ie pH 5> or 9<.


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## Guest (Aug 17, 2008)

blairo1 said:


> > I keep tanks between my regular tap water which is 6 and after using buffer 8.4
> 
> 
> Yup, you and me both bud.
> ...


How reliable and well built is the ph tester? Would you buy it again or recommend it to other hobbyists?

How do you test with it? Is there a probe or something? And could you get a link for a ph calibration solution, or would I just search for "ph 7 calibration"?

And is it flimsy? Like say if I drop it on the floor would it be ruined/break, or would I just have to recalibrate it?

~Ed


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## blairo1 (May 7, 2006)

> How reliable and well built is the ph tester? Would you buy it again or recommend it to other hobbyists?


It's reliable to 0.1 with a +/- 0.1 tolerance (which is pretty much a given). So pretty accurate and in controls against other more expensive probes it came out with the same reading - occasionally it would be .1 out but that's it's tolerance so understandable really. The only issue as I see it with the cheap probes is that they require frequent calibration to ensure their accuracy - whereas expensive probes will stay highly accurate for a much longer period of time without calibration. Some people hate these things, others, like me, realise that they are only a cheap solution but that with some diligence in terms of keeping them well calibrated, they are accurate and last long enough to pay for themselves vs liquid tests, not to mention that you're not having to unleash that nasty stuff down into the drains, which inevitably ends up back in our drinking water.

It uses ATC - which is automatic temperature compensation - so you need to hold it in the water for a good 10-20 seconds to bring it to temp (initially) and this ensures a true reading. It still reads straight away, I'll do a video for you to see how it works, but as you swill it and it adjusts to temp it starts to settle on the reading. Some cheap probes won't have this and it's a PITA as you have to keep checking charts to see what reading = what at different temps. The one I linked you to is ATC.

Yes I would buy it again if I didn't have the money for a more expensive probe, but I've not had to buy a new one yet and it's still accurate. I've dropped it a couple of times, you just need to recalibrate it after a drop or hard bump - it's precision equipment, so it needs to be treated as such. Drops could kill it if you were unlucky, generally drops are more likely to increase the rate at which it loses accuracy, rather than kill it completely. It will need major calibration after a drop, like most precision kit.

I do recommend them, but on the understanding that it is a cheap-o version that _can_ be just as accurate as long as you keep it regularly calibrated (once a week is enough), but that it will need replacing eventually. Mines been used a lot and it's several months old, it still only creeps out .1 over a week period, sometimes not at all, when it starts creeping out by .3 then I'd think about replacing it. For the price and number of times used, well worth it IMO.

Go on ebay and search for - "ph calibration solution". There will be loads of sachet types, don't bother with these - you want the bottled liquid (probably yellow) because you can pour it into a small container to calibrate and as long as the probe and container are clean, pour it back into the bottle for re-use. It's worth replacing this stuff once you think you've used the entire volume two or three times over. Oh and give it a good shake each week too otherwise you'll find it thickening up at the bottom and making loads of jelly like bits.

By rinsing the probe in pure water (I just use filtered fridge water) and drying it well after each use you will maintain it's accuracy for a longer duration.

Here it is in action, I haven't calibrated it in a while which is why it keeps jumping between the .3 and .4, normally it would have sat at .3 after it dropped but because it's creeping out it's at that borderline point where it flips from .3 to .4. Considering I've not recalibrated it in about a month (hasn't needed it) that's really pretty impressive that it's only just starting to creep by .1 .

http://s100.photobucket.com/albums/m15/ ... probne.flv


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## Guest (Aug 19, 2008)

None of the ones popping up on ebay say they use ATC, and one even said to never let the probes dry to always keep them wet...

Any truth to always keeping them wet? And what about the listings not saying they use ATC? Does that mean that they don't or just information they left out?

~Ed


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## blairo1 (May 7, 2006)

If it looks exactly like mine, chances are it has ATC - they're all made in Hong Kong and shipped out to a bunch of different retailers.

Do this search:

pH Meter Digital Aquarium Pool Spa Water Test

A red one should come up, it's $30, you might find one cheaper, but that's the first one that came up for me. It IS ATC and I know that's exactly the same as what I have. There was a yellow one that came up with ph digital test search, but it was a different mould- don't believe it is the same (the one that said to keep the probe wet).

I've never heard about keeping the probe wet - neither with people I've spoken to, or in it's instructions, I dry mine out as best I can after use and you can see it still works. I do always replace the cap though so I guess if there's moisture in the "cloth" it will be retained. Wouldn't hurt to be on the safe side. It's not made any difference to me though.


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## Guest (Aug 19, 2008)

What cloth?


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## blairo1 (May 7, 2006)

The ones that tell you to keep them wet use some sort of cloth in joining the probes or something like that, which is the bit that you're supposed to keep wet (apparently anyway). If that bit dries out the pH meter stops working, apparently.

Like I said the one that mentioned keeping the probe wet is different to mine, mine made no mention of such necessities and after months of being thoroughly dried after each use, it still works perfectly.


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## Toby_H (Apr 15, 2005)

Thank you both for this very informative conversation... I've never really considered getting a PH meter but after hearing such positive results on a reasonably priced unit... it almost seems silly not to...


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## blairo1 (May 7, 2006)

:thumb:


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## Guest (Aug 19, 2008)

Lastly, why would you have to rinse it? Wouldn't it get rinsed in the tank water? And what do you rinse it with? Tap water? And how would you do it? Just stir it in a cup with tap water or hold it under running tap water?


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## blairo1 (May 7, 2006)

> By rinsing the probe in pure water (I just use filtered fridge water) and drying it well after each use you will maintain it's accuracy for a longer duration.


Especially in hard water tanks - you basically don't want deposits on the probe. I just rinse the probe in a cup and dry it with kitchen towel.

:thumb:


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## indigosteve (Mar 5, 2021)

Marduk said:


> blairo1 said:
> 
> 
> > http://www.seapets.co.uk/product-details/stkcode/662550/category/753.html
> ...


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