Ph meter, error during calibration

[lilnug420]

i have these 2 ph meters, one is 1 year old the other 3 years old.


they're both giving error when trying to calibrate, they were stored dry, as the instructions don't say anything about storage solutions.


on the instruction it says if they dry out to immerse them in distilled water for 2-3 h, i did so overnight and they're still giving error, i'm gonna try immersing them for 12h in the 4ph solution as i've read it can help revive them.

i will post a pic of the instructions and the ph meters.


does anyone have experience with these cheap meters? how accurate are they? and how often do you calibrate them? as long as the margin of error isn't higher than 0.25 they're good enough for me as i can't afford the expensive ones​

 

[Bluey]

Have a good read of the below.

It's well written and many of us have been through this the same as you.

https://forum.growweedeasy.com/forum/growing-community/587080-the-tale-of-two-ph-pens

 

[90Gizmo]

Years?! After 3 months I calibrated mine and it wouldn't give the same number when I immediately put it back in calibrating solution. If you got a year out of one you're the big winner with those.
I didn't want to spend big bucks either so I bought quality test strips instead. They are discussed in the above thread as well.

 

[Ckbrew]

They are trash, get rid of them. They may ruin your grow if you let it. Use pH papers.

 

[lilnug420]

They are trash, get rid of them. They may ruin your grow if you let it. Use pH papers.

managed to revive mine, 3 years old, still accurate, not sure what you're talking about... ph papers are as accurate as your eye and judgment

 

[Ckbrew]

Did you read the thread recommended by Bluey? See post number 14 in that thread. pH papers are accurate enough for growing cannabis.

 

[HeavyMetal1]

I have a different unit, but fresh batteries cured the error situation for me.

 

[lilnug420]

Did you read the thread recommended by Bluey? See post number 14 in that thread. pH papers are accurate enough for growing cannabis.

in soil i agree, but in soilless i think being off my 0.5-1 ph point can make a big difference, and personally i don't trust my judgment in reading the scale enough as shades of yellow/orange/green can look quite similar

 

[Ckbrew]

I don't grow in soil.

 

[golfnrl]

Hi lilnug420 I first used a Hannah Instruments PH pen. I've not used the PH strips for the same reasons you have stated. I like the digital readout. I dried out the Hannah too many times and the reading became slooooow. And I had to recalibrate it too often. So I replaced it. Sounds like you might have your issue resolved? When the pen gives an error message what does it say? Does it just say ERR?

 

[Bluey]

Some nutes, especially 2 part ones, have a colouring agent in them which may interfere with using litmus paper and a color chart.

I use the Apera and it works great.

 

[lilnug420]

Hi lilnug420 I first used a Hannah Instruments PH pen. I've not used the PH strips for the same reasons you have stated. I like the digital readout. I dried out the Hannah too many times and the reading became slooooow. And I had to recalibrate it too often. So I replaced it. Sounds like you might have your issue resolved? When the pen gives an error message what does it say? Does it just say ERR?

yep just err

 

[lilnug420]

Some nutes, especially 2 part ones, have a colouring agent in them which may interfere with using litmus paper and a color chart.

I use the Apera and it works great.

yep megacrop too