Live Stoner Chat Whats up with the pH meters?

[MedGrower]

Arrgg! I am so frustrated with my pH meter! I was just measuring the pH of my reservoir this morning and noticed it had fallen down to pH 5.4 according to my meter. I calibrate it from 7.0 every month at minimum and it reads just fine.....but... there is a huge but:

Everytime it reads a really low pH reading like 5.4 or so it goes all nutty and doesn't seem to recover from it until I let it stay on pH storage/cleaning solution for about half an hour or so. As example, I corrected my solution by taking some water out and setting it to 7.8 and applying that back to the reservoir to set the overall pH to around 6.2. Upon rechecking the overall pH of the solution it still showed like 7.2!!! I checked the pH with droptest and it scaled it to around 6.2.

I am so sick and tired of crappy pH meters that promise all the heavenly accurate readings and costs a lot but just lock up on high or low pH values and goes nuts. Do you guys suffer from the same problem? If you are have you solved it somehow? My meter is "Essentials pH meter".

Yeah, I rinse my pH meter with water between every measurement to take the remains of previous solution out of the probe.

 

[Dazed]

Do you keep the probe moist at all times, shouldn't dry out. Also, you probably need to leave the pen in the solution for 15 mins stirring occasionally, that's the only way I used to get a true pH reading when I used to pH.

D

 

[MedGrower]

Yeah I have a screwable cap in it that I fill with actual pH meter probe cleaning / storage solution designed for that specific purpose. 15 minutes??? oh my. I guess I am far too hasty then.

Man I would imagine with 100e that thing should read the pH in seconds. Thanks bro, I will see next time if leaving it for 15 mins would do any good.

 

[Kakarot]

I used the HM Ph 200 I had to buy a little bottle of probe storage solution to keep the electrode wet at all times, there is a little sponge in the cap you drop about 6 droplets in there and it keeps for a good while. Also some 7.0 calibration fluid is nice to have on hand, but yeah always keep the electrode moist and rinse with distilled water after each reading.

 

[Dr Who]

Can you refill the internal solution? It sounds to me as though you might not have a saturated solution inside any more (it should usually be KCl with visible precipitate). Check the instructions to see if refilling/replenishing the internal solution is mentioned, and look for a small refilling hole on the side of the probe, often plugged with a tiny rubber bung thing.

If it's possible it can really do wonders for a seemingly rubbish old electrode

 

[Heavily Medicated]

Are all pH meters like this? I always rinse mine off between every test, and calibrate it regularly with 7.0 test solution, but I never store it in solution or anything. Mine just sits on top the tent when not in use. It was not an expensive meter either, I think I paid like 20.00 for it. Seems to be working good for me after over a year? Maybe some meters are different from others?

 

[MedGrower]

Can you refill the internal solution? It sounds to me as though you might not have a saturated solution inside any more (it should usually be KCl with visible precipitate). Check the instructions to see if refilling/replenishing the internal solution is mentioned, and look for a small refilling hole on the side of the probe, often plugged with a tiny rubber bung thing.

If it's possible it can really do wonders for a seemingly rubbish old electrode

Good point and idea! I need to check that one out when I can! I have pH probe refill / storage solution by Growth Technology so I guess that is the stuff you refill it with?