PH meter problem

I'm having a serious problem with my ph meter. I've had it for only a year and I don't know whats wrong. I recently noticed that when I put it in ph reference solution it reads 8.3 or 8.4. And it won't even let me calibrate it in the sution, but it lets me calibrate it in RO and regular water. My RO water comes out at about 7.0 but I still wanna be accurate as possible. I thought it was the ph solution but I got new solution and the same thing happens. The meter I use is a
Oakton EcoTestr pH 2 Waterproof pH Tester, 0.0 to 14.0 pH Range

That is weird, that you can only calibrate in your water, but not a reference solution. Contact manufacturer, assume that your RO is 7 (which it should be) adjust slightly to bring it to 6.5 (soil) and hopefully they will send you a new tester (within a year for a good tester, they will replace) good luck..

hey , check out Medgrower1 on you tube he just made a video of that exact meter

Have you allowed the probe to dry out?

Dry probe generally means death.


You could try a 24hour soak in tap water. Then try recal.

Or a 24hour soak in KCI solution.


J

jondamon said:

Have you allowed the probe to dry out?

Dry probe generally means death.


You could try a 24hour soak in tap water. Then try recal.

Or a 24hour soak in KCI solution.


J

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I did let it sit in a cup for a night but I put it back in water the next day

Jimdamick said:

That is weird, that you can only calibrate in your water, but not a reference solution. Contact manufacturer, assume that your RO is 7 (which it should be) adjust slightly to bring it to 6.5 (soil) and hopefully they will send you a new tester (within a year for a good tester, they will replace) good luck..

Click to expand...

Hopefully they do cause I take good care of this meter and I'm not trying to come out of pocket for a new one when this one should still work

Marlo95 said:

Hopefully they do cause I take good care of this meter and I'm not trying to come out of pocket for a new one when this one should still work

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Where did you buy it.? I'm pretty sure you will have at least a year warranty. It sucks I know not to have a meter, but your plants will not be fucked with having 7.0 water for awhile. Look at it this way, if your meter is dead, which it probably is (the company will replace I'm sure)it, buy a combo this time(EC/PPM/PH), and you will have a better tool, as long as you have the cash to spring for it. I got a Hanna meter with all the bells and whistles from Amazon (3 year warranty) for $170. Expensive, I know, but it beat paying $330 for the Greenlee that I had that shit the bed recently They all don't last any more (fucking Chinese shit)

This heres exactly why I quickly came to hate the whole PH meter thing real quick.

I hate em but I wouldn't do it without.I regularly use mine as a spoon and did it on Tuesday and had to go get another one... $35 for another Milwaukee...

Crack the internal glass stem of the ph indicating probe and the reading will be frozen. Meaning no matter what solution you put it in (acid like o.j.) will show ph 7. If a ph probe is stored incorrectly, for example with nutrient solution not rinsed off, the there will be growth on the ph electrode. When this happens then the voltage generated in a ph solution changes thus the actual ph. You can only calibrate +\- 1 ph unit or+\- 60 mV. A pH probe has ph 7 inside the glass so placing in pH 7 buffer should give 0 mV. Growth on probe shifts this so it can read up to 60 mV in ph 7. When we calibrate we tell the meter that 60 is pH 7. If the meter is placed in pH 7 and it reads75mV then it will not calibrate. If placed in another solution that is in the 60 mV range then it will accept. Most likely the water is around pH 6 which theoretically would generate -60 mV. If the probe has a 75 mV offset then the pH6 mV would be 15 mV. The meter will accept reading and calibrate showing pH 7. Ro water should not be read with a ph meter. A ph probe needs a solution of 100 uS/cm or more. Ro is 20-30 uS/cm. not enough salt to conduct a proper current. Hanna meters offer cal-check that will tell you if there a problem with the probe or buffer. Meters with cal chech cost a bit more than pens but you will know if the meter is working right.

So I just got a new ph meter for free. Even though the warranty was up they sent me a new one. Should I store it in the ph solution when I'm not using it? What's the best way to take care of it?

try removing/replacing the batteries. let it sit for a few minutes with no batteries.

Marlo95 said:

So I just got a new ph meter for free. Even though the warranty was up they sent me a new one. Should I store it in the ph solution when I'm not using it? What's the best way to take care of it?

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I haven't had good luck with Milwaukee PH006 (or 009, whatever it is). Mine is too twitchy calibrating it. It goes bonkers sometimes, changing its display. I like the $7 EtekCity meter sold on Amazon.

I store mine with a few drops of storage solution in the cap, shake and stand upright. I use probe cleaning solution occasionally. When I had the problem with erratic readings I took the batteries out, left the probe cap off, and let it dry out for 8-12 hours. I agree with a previous post that letting them dry out isn't supposed to be a good idea. But, that's always how I fixed mine. (Maybe algae was growing on the probe and drying killed it.).

Never test RO or distilled water. The lack of ions in the water will slowly kill your meter. This coming from a Blue Lab rep.

nevergoodenuf said:

Never test RO or distilled water. The lack of ions in the water will slowly kill your meter. This coming from a Blue Lab rep.

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can I get a free blue lab?pls

If you do not purchase storage solution then use pH 4 buffer. If you do not have pH 4 then use pH 7. Storage solution is the best since the solution has microbial inhibitors to keep stuff growing. pH 4 is an alternative since bacteria do not grow well at low pH's. It is the reason it is common in the food industry to lower the pH of food products for longer shelf life.

As stated above, never store in purified water. It will cause diffusion of the internal reference electrolyte into the solution and have an osmotic effect in which water will go into the reference cell. Change the 3.5M KCl reference electrolyte changes the reference potential. If you cannot change the reference electrolyte, as with a refillable probe, then the probe is toast.

The purified water also leaches ions from the hydrated layer of the glass indicating probe. If a probe is stored in DI/RO for too long then it should be placed in storage solution to re-establish the hydrated layer.

Storage solution is the best stuff to store pH probes in but I have found that they still dry out if you leave them in the cupboard for a few months. The seal around the solution cup on that eco tester meter you have isn't good enough to stop evaporation. Had one the exact same but itself the same way, dried out. In the bin.

Sorry, I'm not a Blue Lab rep, I have just gone through their sales demo/class. And you can't have my free blue lab pen.

This is my first post so hi all this may help ya it may not even though the thread is old maybe others have the same issue...
The back ground......
I stupidly left mine to dry out in the shed for year maybe and when I found it, I had the same problem it wouldnt calibrate in the 7ph solution it was reading 8.9ph when trying to calibrate.
With a few searches I found this thread and many others, looking for a solution to my problem, the genral answers were never let it dry out!
But i thought surley I can fix it, and to my suprise i did.
This how I fixed mine, funny enough it was by using 4ph buffer to do the actual calibration exactly the same way you are meant to do it with the 7ph buffer solution.
Here are the exact steps I used, hope it helps peoples !
1st step was clean the end with water and dry off.
2nd put the 4ph buffer into a container ( i used an egg holder ).
3rd turn on ph meter wait till you see a reading then put it in the the 4ph solution.
4th the meter will be blinking i believe mine was reading 6.8 in the 4ph solution.
5th when it stops flashing hold the enter button untill the reading says 7.0.
6th now repeat step 1.
7th put the 7ph buffer into a container then repeat steps 3 4 and 5 (7ph solution).
Quick point of what happened with me was when it is blinking this time it was reading very close to 7ph, 6.9 i believe, which is not exactly the 7 you want. But after the calibration it was reading a perfect 7 in the 7ph buffer solution and a perfect 4 in the 4ph solution.
My pen has been working ever since i done this and now i keep it stored the right way.

Marlo95 said:

I'm having a serious problem with my ph meter. I've had it for only a year and I don't know whats wrong. I recently noticed that when I put it in ph reference solution it reads 8.3 or 8.4. And it won't even let me calibrate it in the sution, but it lets me calibrate it in RO and regular water. My RO water comes out at about 7.0 but I still wanna be accurate as possible. I thought it was the ph solution but I got new solution and the same thing happens. The meter I use is a
Oakton EcoTestr pH 2 Waterproof pH Tester, 0.0 to 14.0 pH RangeView attachment 3336831

Click to expand...

Mine did the same thing. Here is what's happening. A build up of minerals from hard water causes the probe to be so far out of calibration that it will not calibrate. Soak the probe in PH down (acid) and lightly scrub it with a tooth brush. Try again to calibrate it.

If you reset to the factory calibration as per the manufacturers instructions and then see what it says in 7.0 standard that will tell you how far it has wandered off since leaving the factory. If it reads over 8.1 it probably will not calibrate. If you can clean the probe enough to get that down to 8.0 or less it should be within range to calibrate. The build up is making the meter think it's in very high ph solution.