# Good ph and kh pen?



## Jona$ (12 May 2020)

Have Jbl dropkit but Think its hard to reed sometimes, is there a better way. As a good ph and kh pen or some like it.

Nothing with just guessing or malfunction after 5 readings.


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## dw1305 (12 May 2020)

Hi all, 





Jona$ said:


> I have Jbl dropkit but Think its hard to reed sometimes, is there a better way. As a good ph and kh pen or some like it. Nothing with just guessing or malfunction after 5 readings.


There isn't really a <"good cheap, accurate pH meter">. They are quite complicated bits of kit, and you need one with two point buffering etc. 

Carbonate hardness is a bit different, there <"isn't really a meter for it">, but you can <"measure alkalinity"> via an <"acid base titration"> (using an acid of known strength). That is what the Jbl test kit does. 

My suggestion is to <"buy a conductivity meter">. The conductivity of your tap water is fairly closely correlated with its hardness (both dKH & dGH), because most of the ions will be Ca++ and HCO3- ions which come from dissolved limestone (CaCO3). 

I measured the conductivity of the <"water in the tanks, water butts and tap supply"> a few days ago. The readings were:

Water butt = 90 microS
Tank = 104 microS
Drinking water tap = 680 microS
Softened water (<"ion exchange with NaCl">) = 740 microS
cheers Darrel


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## MrClockOff (22 Mar 2021)

Hi all,
Has anyone used this PH-80 – HM Digital ? Any good?


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## dw1305 (23 Mar 2021)

Hi all, 


MrClockOff said:


> Has anyone used this PH-80 – HM Digital ? Any good?





> One-touch automatic digital calibration
> ............................
> Factory Calibrated: The PH-80 meter is factory calibration to pH 7.0.
> Includes a translucent cap, batteries, storage solution and pH 7.0 buffer (powder)


It is not ideal, two point calibration would be much better.  If I had ~£50 I would spend it on a a conductivity meter, rather than a pH meter. 

cheers Darrel


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## MrClockOff (23 Mar 2021)

dw1305 said:


> If I had ~£50 I would spend it on a a conductivity meter, rather than a pH meter.


Could you please elaborate on this in more detail? 
Specifically how to build Ph profile while dissolving CO2 and using EC meter? Is the target the same - one unit drop?
I can see wide range of prices for EC meters online. I have ~£50 available.
Need to educate myself on this subject )


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## dw1305 (23 Mar 2021)

Hi all, 


MrClockOff said:


> Specifically how to build Ph profile while dissolving CO2 and using EC meter?


No, you can't unfortunately.  

The issue for me is that I wouldn't trust that meter to  give you an accurate pH profile.  I'm not a CO2 user, so I don't have practical experience of constructing a pH profile during CO2 addition. If you have hard water? you are more likely to get an accurate pH measurement, because it is easier to measure pH in high ionic strength solutions. 

The drop checker is fairly accurate, but you have issues with the lag while the CO2 diffuses into the 4dKH and bromothymol blue pH indicator. 

cheers Darrel


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## MrClockOff (23 Mar 2021)

dw1305 said:


> No, you can't unfortunately.
> 
> The issue for me is that I wouldn't trust that meter to give you an accurate pH profile. I'm not a CO2 user, so I don't have practical experience of constructing a pH profile during CO2 addition. If you have hard water? you are more likely to get an accurate pH measurement, because it is easier to measure pH in high ionic strength solutions.
> 
> ...


This all makes sense now. My fish tank water has 18GH and 9KH which sounds good re using PH meter and accuracy of measurements. 
My drop checker has required  lime green colour and is steady from start until the end of photoperiod. 
Also I have added additional power head to help with water circulation but my plants still showing CO2 deficiency and quite bad..
Need to see if CO2 is stable thorough the whole photo period..

Thanks a lot for valuable  info 👍


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## jaypeecee (23 Mar 2021)

Hi Folks,

For anyone considering the purchase of a reliable low-cost pH meter, the following is hard to beat:









						HI-98100 Checker Plus pH Tester
					

The easy to use Checker plus is a real favourite with students and researchers due to its clear LCD display and long thin pH electrode. The checker offers automatic calibration and buffer recognition, calibrated buffer tags, and a stability indicator.




					www.hannainstruments.co.uk
				




I used one for years and it gave me good, reliable service. But it is a tad more expensive than £50.

Another manufacturer that's worth considering is Extech Instruments.

It is simply false economy to purchase anything much cheaper than those I have listed above.

JPC


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## jaypeecee (23 Mar 2021)

Hi Folks,

Just realized that @Jona$ was also expressing an interest in measuring conductivity/TDS. I would advise against buying the HM Digital TDS-4TM. I had to return one as it soon developed a defect. The plastic membrane over the push buttons started to peel away from the meter body. In so doing, there was a very real risk of water ingress into the meter. I contacted the manufacturer about this but never got a reply. Very disappointing.

JPC


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