Testing a ph meter

[papa canna]

Is there a good way to "test" my ph meter. I just got one and calibrated it, and when i went to use it the numbers seem a bit odd. It saying that my tap water comes out of the tap at 8.1 that seems a bit high. It also says that my watering solution which i tried to put at about 6.5 using the color coder from general hydroponics was 7.8!!! if it were really 7.8 wouldn't my little clones be showing signs of unhappiness?

 

[jeroly]

There are testing solutions available for pH calibration. Two came with the meter I bought...try Amazon or your local hydro store.

 

[Richard Drysift]

Yes you can get the calibration solution that stay at 7 to set your meter. Keep in mind some meters need the element to be stored wet in order to stay accurate. You can test a base like vinegar that should read at 3 ph but honestly the drops are more accurate in my exp. Ph issues take awhile to show especially in soil; maybe a week or more but in hydro it will be apparent much faster like within a few days.

 

[papa canna]

I ordered seperate bottles of calibration solution, but i wasn't sure if those would be good for actual testing because in the box it says that the meter is suppose to recognize certain solutions in order to be calibrated properly. didn't really dawn on me until after i made the thread. so I can just test the 7.0 fluid?

 

[Dumme]

I ordered seperate bottles of calibration solution, but i wasn't sure if those would be good for actual testing because in the box it says that the meter is suppose to recognize certain solutions in order to be calibrated properly. didn't really dawn on me until after i made the thread. so I can just test the 7.0 fluid?

7.0 or 4.0 liquid should be read by your meter as 7.0 or 4.0. It doesn't matter the namebrand.

 

[Richard Drysift]

I ordered seperate bottles of calibration solution, but i wasn't sure if those would be good for actual testing because in the box it says that the meter is suppose to recognize certain solutions in order to be calibrated properly. didn't really dawn on me until after i made the thread. so I can just test the 7.0 fluid?

Yep.... You just dip in your calibration solution & reset to 7 using that tiny screw on the back- then it'll stay accurate for awhile...I used to store mine upright with the solution in the cap & it'll stay good for a long time..

 

[papa canna]

Yep.... You just dip in your calibration solution & reset to 7 using that tiny screw on the back- then it'll stay accurate for awhile...I used to store mine upright with the solution in the cap & it'll stay good for a long time..

I'll test that a little later tonight, but i dont think i have the screw to which you speak of. I bought this: http://www.amazon.com/gp/product/B00MG3VF7Q

 

[Kingrow1]

I use a bluelab digital ph meter and althought the probe needs to be stored wet i was always told water is bad and instead it should be stored in KCL solution. This is a 3mol solution of Potassium Chloride, chemical name is KCL. This solution not only keeps the probe clean but rehydrates and keeps the probe hydrated

The calibiration above with ph solutions to either 4, 7 or 10 is correct but some need two point calibaration or calibarating with two different ph solutions i.e ph4 and ph7 (not that important which two but two point calibaration means it needs two points of reference). A one point calibaration probe only needs one solution to check, either of the ph4 or ph7 or ph10,doing a two point calibaration on a one point calibaration probe isnt needed.

The part that i do that you dont before calibaration is to leave the probe soak for 24 hours in a cup of KCL solution to rehydrate the probe and keep it from impurities trapping in the membrane etc etc. Only after this 24hour soak do i re-calibarate my meter. This is a once weekly/monthly thing depending on my inner laziness.

I use Ionics KCL probe storage solution and keeps my ph meter sweet for a couple years of accuracy. I use to have a cheaper one point meter but no where near as accurate as the blue lab and im reading hannas version up for £150 is even more accurate again, you get what you pay for a ph meter these days.

 

[papa canna]

I use a bluelab digital ph meter and althought the probe needs to be stored wet i was always told water is bad and instead it should be stored in KCL solution. This is a 3mol solution of Potassium Chloride, chemical name is KCL. This solution not only keeps the probe clean but rehydrates and keeps the probe hydrated

The calibiration above with ph solutions to either 4, 7 or 10 is correct but some need two point calibaration or calibarating with two different ph solutions i.e ph4 and ph7 (not that important which two but two point calibaration means it needs two points of reference). A one point calibaration probe only needs one solution to check, either of the ph4 or ph7 or ph10,doing a two point calibaration on a one point calibaration probe isnt needed.

The part that i do that you dont before calibaration is to leave the probe soak for 24 hours in a cup of KCL solution to rehydrate the probe and keep it from impurities trapping in the membrane etc etc. Only after this 24hour soak do i re-calibarate my meter. This is a once weekly/monthly thing depending on my inner laziness.

I use Ionics KCL probe storage solution and keeps my ph meter sweet for a couple years of accuracy. I use to have a cheaper one point meter but no where near as accurate as the blue lab and im reading hannas version up for £150 is even more accurate again, you get what you pay for a ph meter these days.

while the meter is fairly inexpensive, it got good reviews and after calibrating it using this solution (http://www.amazon.com/gp/product/B00BUV7L96) it seems pretty acurate. It tests the 7.0 solution from this solution pack at 7.1 which is fair given that it's accuracy was listed +- .2

 

[2ANONYMOUS]

once calibrated test it in vinegar should be 2.4 - 2.5 if its pen reads it then your good to go

 

[Kingrow1]

while the meter is fairly inexpensive, it got good reviews and after calibrating it using this solution (http://www.amazon.com/gp/product/B00BUV7L96) it seems pretty acurate. It tests the 7.0 solution from this solution pack at 7.1 which is fair given that it's accuracy was listed +- .2

Yer most meters will be good enough, they are all quite basic.

 

[papa canna]

once calibrated test it in vinegar should be 2.4 - 2.5 if its pen reads it then your good to go

2.4 on the dot. worked like a charm. thanks

 

[2ANONYMOUS]

glad i can help sometimes i when out of solution i do just that and subtract or add the difference and what ever i am ph'n add or subtract and it will tell me what ph is

 

[papa canna]

glad i can help sometimes i when out of solution i do just that and subtract or add the difference and what ever i am ph'n add or subtract and it will tell me what ph is

if you run out again you should check the solution i linked. a fair price for all the necessary compounds.

 

[since1991]

I keep my blue lab combo meter pH probe in the cap with the storage solution. I like to replace mine every 6 months to a year. After awhile they get slow and i question the accuracy. As they get older i like to keep them in the solution to ne tested for a good half hour. They are finicky by nature. Keep them calibrated and stored in kcl solution and replace when theh start acting funny. Newer ones are quick to give readings. The bluelab pens are nice. Same thing as thw probe meter but they are not replaceable. Once they start to go you have to buy a new one. Combo meter is pricey but its a one time purchase except for the probe itself.

 

[Kingrow1]

I keep my blue lab combo meter pH probe in the cap with the storage solution. I like to replace mine every 6 months to a year. After awhile they get slow and i question the accuracy. As they get older i like to keep them in the solution to ne tested for a good half hour. They are finicky by nature. Keep them calibrated and stored in kcl solution and replace when theh start acting funny. Newer ones are quick to give readings. The bluelab pens are nice. Same thing as thw probe meter but they are not replaceable. Once they start to go you have to buy a new one. Combo meter is pricey but its a one time purchase except for the probe itself.

Do you rehydrate the probe every couple of weeks by submerging the probe in a cup of storage/KCL solution as recomended? If not this will extend the life and keep it in better condition.

I do this every couple weeks or so and re-calibrate after.

 

[since1991]

No. The probe comes with a sealed cap dealy thats ALWAYS filled with pH storage (kcl) solution.

 

[since1991]

Never let the glass bulb dry. Not even a little.

 

[Kingrow1]

No. The probe comes with a sealed cap dealy thats ALWAYS filled with pH storage (kcl) solution.

Here is bluelabs video on the meter....

https://m.youtube.com/#/watch?v=EYL62M9Y9CQ

They say to do a 24hour Kcl soak every 30 days and when bought new before first use, they even write it on the video as reference.

When people refer to hydrating a probe they dont just mean keeping the probe wet they mean hydrating the gel layer on the probe surface. Kcl does this which is why i asked if you were hydrating the probe every few weeks.

I hydrate my probe before calibaration with a 24 hour kcl soak but if i still had slowness or inaccuracy id refer to their cleaning process and solution which will futher help remove contaminants and chemical particles picked up from everyday use.

My bluelab runs perfectly and im guessing that any problems you have are down to the different ways we look after our probes.

I hope the video makes sense of why you need to keep a probe properly hydrated.

 

[since1991]

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.