BluLab pH pen won't calibrate in 4.0 solution

[TCH]

Stopped into my local grow shop today to pick up a couple things and asked if they could test my meters vs known good meters and she informed me that they will clean and calibrate meters whenever for people. That was a nice surprise. My pH pen calibrated just fine to the 7.0 solution but wouldn't get all the way down to calibrate in the 4.0 solution. She recommended that I try to soak it in the 4.0 solution for a while and try again. She said she has had some luck even soaking overnight. So, I'm headed home to soak that puppy for an hour or 2 and then I'll try again. If it still doesn't work, I'll soak it overnight and try it one last time.

Has anybody had luck with this method?

Worst case scenario, what is a good and inexpensive pH meter that hopefully reads faster than the BluLab and is preferably cheaper as well?

 

[Billy the Mountain]

Stopped into my local grow shop today to pick up a couple things and asked if they could test my meters vs known good meters and she informed me that they will clean and calibrate meters whenever for people. That was a nice surprise. My pH pen calibrated just fine to the 7.0 solution but wouldn't get all the way down to calibrate in the 4.0 solution. She recommended that I try to soak it in the 4.0 solution for a while and try again. She said she has had some luck even soaking overnight. So, I'm headed home to soak that puppy for an hour or 2 and then I'll try again. If it still doesn't work, I'll soak it overnight and try it one last time.

Has anybody had luck with this method?

Worst case scenario, what is a good and inexpensive pH meter that hopefully reads faster than the BluLab and is preferably cheaper as well?

Apera makes quality pH meters at reasonable prices; $50 - $80 or so

I have a PH60, and have no issues calibrating w/ 4.0 and 7.0 solution; it only takes a minute.

 

[TCH]

Apera makes quality pH meters at reasonable prices; $50 - $80 or so

I have a PH60, and have no issues calibrating w/ 4.0 and 7.0 solution; it only takes a minute.

View attachment 5306325

How fast does it read ph when taking measurements?

 

[rkymtnman]

Stopped into my local grow shop today to pick up a couple things and asked if they could test my meters vs known good meters and she informed me that they will clean and calibrate meters whenever for people. That was a nice surprise. My pH pen calibrated just fine to the 7.0 solution but wouldn't get all the way down to calibrate in the 4.0 solution. She recommended that I try to soak it in the 4.0 solution for a while and try again. She said she has had some luck even soaking overnight. So, I'm headed home to soak that puppy for an hour or 2 and then I'll try again. If it still doesn't work, I'll soak it overnight and try it one last time.

Has anybody had luck with this method?

Worst case scenario, what is a good and inexpensive pH meter that hopefully reads faster than the BluLab and is preferably cheaper as well?

what do you store the probe in?

i love my milwaukee mw101. it even took a quick dip in my res a few years ago and didn't faze it.

 

[Billy the Mountain]

How fast does it read ph when taking measurements?

Are you sure you're calibrating it correctly?
I don't think there should be any expectation for the meter to eventually arrive at 4.0 on its own, no matter how long its soaking.
IIrc, w/ the Apera, you leave it in the solution for a bit and then press the cal button to reference the meter's displayed value to the calibration solution.
I would expect the Bluelab to work similarly but haven't used one.

Usually a few seconds for a reading, maybe 5 - 10 seconds worst case scenario

 

[Jjgrow420]

If it won't calibrate in 4 the 4 has likely gone bad. Buy your own and do it yourself. I wouldn't trust a grow store employee to tie my shoes never mind calibrate precision instruments

 

[DCcan]

Just a good cleaning might help.

Method 1
Soak the electrode in a 0.4 molar concentration of HCl (hydrochloric acid) for 10 minutes, then rinse the electrode with deionized or distilled water. This should remove any organic protein from the glass electrode and the surface of the reference electrode.

Method 2
Soak the electrode in a 3.8 or 4.0 molar KCl (potassium chloride) solution heated to 50°C for 1 hour. Allow the KCl solution to cool down to room temperature, then rinse the electrode with deionized or distilled water. This will open and clean the reference electrode of all contaminants.

Method 3
Soak the electrode in a 4.01 pH buffer solution , heated to 50°C for 1 hour. Allow the buffer to cool down to room temperature, then rinse the electrode with deionized or distilled water. This will open and clean the reference electrode.

Method 4
After each use, rinse the electrode in 0.5 N or 1% HCl. If you have a build-up of oil or protein contaminants, try soaking the electrode in warm detergent and water solution. Degreasing dishwashing detergents or stain removing pre wash pretreatment are ideal for this: any brand will do. An overnight soak may be needed if build-up is heavy. Then rinse the pH sensor in deionized or distilled water and soak for 10 minutes in 1% HCl. Rinse the pH sensor in deionized or distilled water and check in buffers. If the pH sensor calibrates to buffers it can be used in tests. When the pH electrode cannot be calibrated even after attempts to clean it, it must be replaced.

Method 5
For protein removal, soak the pH electrode in contact lens enzymatic cleaner solution overnight. The enzymes will remove proteins from glass and plastic.

Storage
Note: never store your PH electrode in distilled water

• Bluelab uses 4M KCI, Apera uses 3M KCI, others use 1M KCI solution, proper chemical makes it read faster and more accurately and extends service life.
• It is also possible to use a 1:1 mixture of pH 4 buffer and 3..4 M KCl solutions.

 

[TCH]

what do you store the probe in?

i love my milwaukee mw101. it even took a quick dip in my res a few years ago and didn't faze it.

It is stored with its cap on and I use the kcl drops from blulab

 

[TCH]

Are you sure you're calibrating it correctly?
I don't think there should be any expectation for the meter to eventually arrive at 4.0 on its own, no matter how long its soaking.
IIrc, w/ the Apera, you leave it in the solution for a bit and then press the cal button to reference the meter's displayed value to the calibration solution.
I would expect the Bluelab to work similarly but haven't used one.

Usually a few seconds for a reading, maybe 5 - 10 seconds worst case scenario

She was calibrating it per the BluLab method.

 

[TCH]

If it won't calibrate in 4 the 4 has likely gone bad. Buy your own and do it yourself. I wouldn't trust a grow store employee to tie my shoes never mind calibrate precision instruments

The solution was a fresh bottle that she opened while I stood there. I trust her and her process. That said, there are a few I wouldn't trust any further than I could throw em. I will be calibrating it on my own and then reaching out to bluelab if the problems repeat.

 

[Billy the Mountain]

The shoelace theory seems likely.

The manual says nothing about leaving it in the 4.0 solution for hours hoping for a better result.

It does state a requirement to initially soak in storage solution for 24 hours before using or calibration.

Did she do that before attempting calibration?

 

[effexxess]

Bluelab uses 4M KCI, Apera uses 3M KCI

Milwaukee instruments uses 3.5M KCl

 

[TCH]

The shoelace theory seems likely.

The manual says nothing about leaving it in the 4.0 solution for hours hoping for a better result.

It does state a requirement to initially soak in storage solution for 24 hours before using or calibration.

Did she do that before attempting calibration?



View attachment 5306334

The manual says before initial use, hydrate the unit by soaking. Then calibrate it. This wasn't before the first use. The meter has been kept clean and stored with the bluelab kcl solution in the lid as it is supposed to be. She took and cleaned the probe and mentioned how clean it actually was and then calibrated it by the Bluelab procedure as shown in the picture. I may have mis-stated what she said. Either way, it calibrated fine in the 7.0 solution. It would not calibrate in the 4.0 solution. So, that is when she said that in the past when they don't calibrate, she has tried again after soaking in the 4.0 and was then able to get them to calibrate.

The meter was bought 12.5 months ago so its out of the 12 month warranty period, although I will email bluelab just for shits and grins if it won't calibrate again. With an 18 month lifespan, it's worth trying her way as one last ditch effort. Either way, it will need to be replaced I'm sure.

 

[BongerChonger]

I don't personally recommend HM Digital brand pH meters, if you end up needing to replace, as it sounds like you might need to.

I've gone through 2x HM Digital ph-200's in a matter of weeks. Same deal, couldn't calibrate properly and calibration would drift.
First one was dead on arrival and replacement lasted a couple months.
Frustrating!

 

[Jjgrow420]

I moved from bluelab to hanna

 

[Nizza]

clean probe
soak in KCL for a few days
rinse, dry, hit cal-- place into 7.0
rinse, dry, hit cal-- place into 4.0

If you let the probe go dry it may be dead. I bought the Leap probe from bluelab which has a replaceable probe and much faster readings, it works in soil too and I really like it!

 

[BongerChonger]

I bought the Leap probe from bluelab which has a replaceable probe and much faster readings, it works in soil too and I really like it!

I just got the same with the EC combo. I like it a lot too.

 

[Drop That Sound]

Did you try putting new batteries in? After a year, they could be low\bad.. Your supposed to cal after changing them btw, so it obviously effects the operation of the device, right?. I've had meters (dunno about blue labs though) that wouldn't even work\cal properly out of the box until I put a new name brand battery in. I ran back to drops after dealing with cheaper meters. Seen to many problem threads with expensive ones to upgrade, and to me it seems like you spend more time monitoring the meters than the res anyway.

Hope the soak works though!

 

[TCH]

Did you try putting new batteries in? After a year, they could be low\bad.. Your supposed to cal after changing them btw, so it obviously effects the operation of the device, right?. I've had meters (dunno about blue labs though) that wouldn't even work\cal properly out of the box until I put a new name brand battery in. I ran back to drops after dealing with cheaper meters. Seen to many problem threads with expensive ones to upgrade, and to me it seems like you spend more time monitoring the meters than the res anyway.

Hope the soak works though!

After it wouldn't calibrate the 2nd time, she put a brand new battery in it and tried again.

 

[lusidghost]

Apera makes quality pH meters at reasonable prices; $50 - $80 or so

I have a PH60, and have no issues calibrating w/ 4.0 and 7.0 solution; it only takes a minute.

View attachment 5306325

I was a Bluelab loyalist for years, but then a new pen and its replacement both died after only a couple of months. The company wanted me to send the pen back and wait like two weeks for a third, so I bought one of these instead. I've been very happy with it. My favorite thing about it is how the display's backlight can be turned on and off manually. That's really helpful when it's down in the res for more than a few seconds.