your drift on the pH pen

Gquebed

Gquebed

Well-Known Member
So my pH pen is on the outs and i bought a new one. After two weeks i took it back because i had to recalibrate it every watering. The guy exchanged it. Same prob with that second pen, but worse. So i took it back. The guy said the first pen i brough back was fine and he tried to give it back. So i asked him to dip it in the calibration solution and it came up 7.2 and 4.3 and he said it had been calibrated the night before. I wouldnt take it.

Anyway... thought i would ask here. How much drift on your pH pen is acceptable?

My old Blue Lab pen was rock solid. It would drift from 7.0/4.1 to 7.2/4.3 over a month. (I have to calibrate every watering now, but it is almost 2 years old) Am i expecting to much to get a new pen just as solid?
 
delstele

delstele

Well-Known Member
Seems like quality control has taken a back seat as of late. A lot of shit is not the same quality it was a few years ago.
 
Flowki

Flowki

Well-Known Member
Gquebed said:
So.....

....nobody uses pH pens?
Click to expand...
You can get ph pen storage solution to place in the cap after every use (depending on ph pen). It supposedly slows the drift considerably. If it gets dry or is allowed to sit in or covered in nutrient water it will drift quicker/malfunction due to organic build up etc. I believe the more expensive ph meters are better equipped and designed to sit in the tank.

Drifting from 7.0 to 7.2 over night is either real poor storage practice or it is a dodgy maker/batch. Or perhaps the ph solution could be off. I'd bet in order of above on the issue.
 
Gquebed

Gquebed

Well-Known Member
OneHitDone said:
I have had terrible luck with the newer Blue Lab pens crapping out after like a month for some reason even with proper care.
I switched to Hanna, you may want to check them out and they have some nice lower priced models

http://hannainst.com/groline-hydroponics-ph-ec-tds-meters-testers
Click to expand...
I heard Blue Lab had a run of producing bad pens, but i've been lucky with them.

The Hanna pens i had 5 or 6 years ago were pretty bad which was why i switched. I guess they've improved?
 
bk78

bk78

Well-Known Member
I just checked my HM yesterday after not calibrating it for at least 4 months. It was 1 point off at 6.9

been running strong for well over 2 years with me letting the storage solution run dry multiple times
 
downhill21

downhill21

Well-Known Member
bk78 said:
I just checked my HM yesterday after not calibrating it for at least 4 months. It was 1 point off at 6.9

been running strong for well over 2 years with me letting the storage solution run dry multiple times
Click to expand...
Ive been super sloppy about calibrating mine, too.
 
Renfro

Renfro

Well-Known Member
Gquebed said:
So my pH pen is on the outs and i bought a new one. After two weeks i took it back because i had to recalibrate it every watering. The guy exchanged it. Same prob with that second pen, but worse. So i took it back. The guy said the first pen i brough back was fine and he tried to give it back. So i asked him to dip it in the calibration solution and it came up 7.2 and 4.3 and he said it had been calibrated the night before. I wouldnt take it.

Anyway... thought i would ask here. How much drift on your pH pen is acceptable?

My old Blue Lab pen was rock solid. It would drift from 7.0/4.1 to 7.2/4.3 over a month. (I have to calibrate every watering now, but it is almost 2 years old) Am i expecting to much to get a new pen just as solid?
Click to expand...
Do you store the probe immersed in KCl solution?
 
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