• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

Testing a ph meter

since1991

Well-Known Member
Are you referring to the Bluelab Pen or meter? The remote probe meter comes with a sealed vial....always filled with kcl solution. The pen (i used to have one and several other brands) you have to keep a small piece of sponge or moist paper towel filled with kcl in the storage cap. At least thats what i did.
 

since1991

Well-Known Member
Yeah your talking about the Bluelab pH pen. They are nice. But when they start to go bad (all pH pens or remote probes will go bad eventually) you have to buy a new pen. That little glass globe is not replaceable. I bought the combo meter with remote probes for measuring EC and pH years ago. Now when the pH probe goes bad i just buy a replacement for 60$ as opposed to buying a whole new pen for 120$
 

Kingrow1

Well-Known Member
Ive seen the video. The sealed storage vial that comes with my probe is always filled with kcl storage solution. Its always soaking except for the brief period when iam using it in solutions to be tested. I change it about every couple weeks. Mine works great. I have the bluelab cleaning kit also. Clean the probe and ec probe once every 2 months. I replace the pH probe about once a year or when it gets slow.
The cap is very ineffective at keeping the probe hydrated and thats why bluelab ask that you do a soak every 30 days.

A more exspensive ph meter will be soaked constantly everytime its not used in kcl solution which is a lot different to the cap storage on a pen style meter.

Whatever you do is cool but bluelab use the kcl soak on their cheaper models for a very good reason.
 

since1991

Well-Known Member
Yeah i gave up on pens awhile ago. From Hannah to Millwaukee to Oakton....even if they moistioned the little sponge in the cap with kcl it dries more than not from sitting in a wharehouse or hydro store shelf. By the time you buy it its already dried....and dead. Remote probe meters with the fancy little sealed vial is the smart way to go. Pricey but i was tired of buying junk pens.
 

Kingrow1

Well-Known Member
Yeah your talking about the Bluelab pH pen. They are nice. But when they start to go bad (all pH pens or remote probes will go bad eventually) you have to buy a new pen. That little glass globe is not replaceable. I bought the combo meter with remote probes for measuring EC and pH years ago. Now when the pH probe goes bad i just buy a replacement for 60$ as opposed to buying a whole new pen for 120$
Pens arent designed as well as the bigger models, technically the cap should be cleaned as well as that can hold contaminents as well.

The reason behind the pens is they are cheaper so easily replacable and hence why not as long lasting through its cheaper design.
 

Kingrow1

Well-Known Member
Yeah i gave up on pens awhile ago. From Hannah to Millwaukee to Oakton....even if they moistioned the little sponge in the cap with kcl it dries more than not from sitting in a wharehouse or hydro store shelf. By the time you buy it its already dried....and dead. Remote probe meters with the fancy little sealed vial is the smart way to go. Pricey but i was tired of buying junk pens.

You are right and you get what you pay for in the ph meter market. When my bluelab fails i will get a non pen style meter but i cant fault my bluelab atm.
 

since1991

Well-Known Member
The best pens ive ever used was the Bluelab. I like the lighted lcd screen. I had one for awhile but when it finally died (they all do) i said hell with this and got the meter. Pricier than pens initially but cheaper in the long run beacause the glass bulb is replaceable. Hannah and the rest make replaceable pens but that was a pain the the ass. Hannah was king of hobby hydroponic testing gear for years. Bluelab came along and took over. Bluelab is by far the better of all of them.
 

Kingrow1

Well-Known Member
The best pens ive ever used was the Bluelab. I like the lighted lcd screen. I had one for awhile but when it finally died (they all do) i said hell with this and got the meter. Pricier than pens initially but cheaper in the long run beacause the glass bulb is replaceable. Hannah and the rest make replaceable pens but that was a pain the the ass. Hannah was king of hobby hydroponic testing gear for years. Bluelab came along and took over. Bluelab is by far the better of all of them.
Id say their pens are worth it if you cant afford the next model up, theyve certainly impressed me enough to stay with them.
 

since1991

Well-Known Member
You wanna talk about next step up....look at what they use in laboratory's for testing pH. Bench models.....wow!!!! Check it out on google.
 

Kingrow1

Well-Known Member
Ive used some at school and university, they do a lot more than just ph, been trying to steal one from my local colleges lab department for quite a while now :-)
 

Gquebed

Well-Known Member
Wierd thing... i wonder if anybody else has experienced this with the Blue lab ph pens:

When i feed i fill three buckets with the same amount of water. I add the nutes in equal amounts to each bucket. I check ppm to make sure each bucket is about the same. The nutes lower the ph quite a bit but not enough. So Then i add a bit of pH down to each bucket. This is when i bust out my pH pen. I put it in the first bucket and it usually reads about 7.2ish, which is where all three buckets should be, given they have been measured out almost identically. Then i add pH down to that first bucket until i get to 6.3ish, where i like it.

Then i move on to the second bucket. You would think that the starting ph would be the same 7.2ish as the first bucket, but it never is. Same thing with the third bucket. They both read about 6.3 even though neither have recieved 3ven close to the same amount of pH down as the first bucket. Its like the ph pen has a memory.

So i turn it off and rinse it and test again. Same thing. I check calibration with the fluid. A good...

Wtf???

I dont get it. Plants are fine, but this mystery picks my ass...

Anybody else experi2nce the same?
 

since1991

Well-Known Member
Yes....the very nature of the glass bulb probe needs time to settle. Especially if its older. Newer ones are much quicker. That bulb is somewhat semi permeable. First make sure your calibrated.... 2 point preferably. Test one bucket....leave it in there for and hour. Take your reading. Jot it down. Rinse off the probe in water. Test the second bucket....reapeat doing them all. Readings should be the same or close provided all nutrient and pH down measurement dosage was the same for all buckets. Its a time thing with pH probes. Takes a while to settle. Have you ever " strirred" with the probe and get different erratic readings? Sure you have. So have i. Got to give it a half hour or hour to settle on a number that does not fluctuate. Thats is the true pH reading number. They are not quick and to the point like simple electrical conductivity probes. With pH probes...slow analog is an understatement.
 

Kingrow1

Well-Known Member
I just put it in and after a few seconds i have an accurate ph reading, had my bluelab quite a few months and never once has it been out or slow, it has a one year guarentee for this so if it under a year old this shouldnt ever happen.
 

since1991

Well-Known Member
Actually when refilling and resetting nutrient solution tanks its a good idea to take another reading the next day to get a more accurate pH reading. This does not really apply to growers using reverse osmosis water that is at or near 0 in electrical conductivity.
 

Flowki

Well-Known Member
I tried using aquarium ph7.0 powder but it never got the calibration solution ph to 7.0 easily. I tried many types of water, including boiling it a few times to try and remove some elements that may have been effecting ph. Only once I got it to 7.0 and the rest it got to 6.8. I knew this by also testing the water with regular ph test kit and general idea of tap water ph range.

Could have worked but didn't, take my mistake and avoid anything but the right stuff. What I did learn though, is many types of bottled water you can buy claim to have X ph. One even claimed to have 7.0. All were off the mark by quite a few .point
 

Gquebed

Well-Known Member
How long have you had your Bluelab pH pen? Newer ones are quick.
Mine is about 10 months old now.

I dunno.... my pen seems pretty quick. When I pull it out of the bucket and drop it into a cup full of water for a rinse it registers the new pH in just a few seconds, like 5 to 10... then I drop it in the next bucket and it goes right back down to the 6.3ish in a few seconds...

I think tonight, just for a test, I'm going to have both calibration solutions ready and some rinse water and I'll I see what's what....
 

Gquebed

Well-Known Member
And the winner is....

A bad battery...

Fuck me... ive been phing with a bad battery for i dunno how long....
 
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