I was looking around for reviews on different pH meters and noticed that there are very mixed reviews for a lot of different meters. I work in a science lab and use pH meters on a regular basis and noticed that some people with non working meters are probably not caring for them properly.
There are several types of pH electrodes. The ones suitable for hydroponics use are probably double junction type as organics, proteins, high sodium conc, etc damage the single junction type.
Never store the pH meter in distilled water or low ion water. It leaches out the ions in the probe and degrades it. You can store in tap water for short term, but it's probably better to store it in 4.0 calibration solution. 7.0 can also be used but I think 4.0 is better (or buy storage solution). Place a few drops of 4.0 solution in the cap and cap it.
Don't wipe the glass bulb (I saw someone mention cleaning it with a toothbrush...
) Proper way is to rinse quickly with distilled or tap water, and blot the end (best to use optic paper, paper for cleaning eye glasses) gently, don't wipe, it scratches the glass bulb.
Calibrate using at least 2 solutions that bracket the reading you're trying to get (4.0 and 7.0 for us since you're probably measuring to 5.X)
Don't let the probe dry.
When you first get the meter you need to condition the probe. If you let it dry you need to recondition the probe.
place the electrode in either
4 molar KCl (probably don't have this at home)
4.01 or 7.0 calibration solution for 1 hour or overnight
It's a good idea to get some litmus paper and check the calibration solutions from time to time cause they can get contaminated. Pour the solution into another small container with a screw on cap and use that for calibration so you don't contaminate the whole bottle. You can reuse calibration solution a few times as long as your careful to rinse with deionized water and blot clean each time and you cap the used solution to make it air tight. Try to keep those solutions at RT (about 20 C)
For those with slow reading or non working meters, try to recondition it, it might perk up.
There are several types of pH electrodes. The ones suitable for hydroponics use are probably double junction type as organics, proteins, high sodium conc, etc damage the single junction type.
Never store the pH meter in distilled water or low ion water. It leaches out the ions in the probe and degrades it. You can store in tap water for short term, but it's probably better to store it in 4.0 calibration solution. 7.0 can also be used but I think 4.0 is better (or buy storage solution). Place a few drops of 4.0 solution in the cap and cap it.
Don't wipe the glass bulb (I saw someone mention cleaning it with a toothbrush...
) Proper way is to rinse quickly with distilled or tap water, and blot the end (best to use optic paper, paper for cleaning eye glasses) gently, don't wipe, it scratches the glass bulb.Calibrate using at least 2 solutions that bracket the reading you're trying to get (4.0 and 7.0 for us since you're probably measuring to 5.X)
Don't let the probe dry.
When you first get the meter you need to condition the probe. If you let it dry you need to recondition the probe.
place the electrode in either
4 molar KCl (probably don't have this at home)
4.01 or 7.0 calibration solution for 1 hour or overnight
It's a good idea to get some litmus paper and check the calibration solutions from time to time cause they can get contaminated. Pour the solution into another small container with a screw on cap and use that for calibration so you don't contaminate the whole bottle. You can reuse calibration solution a few times as long as your careful to rinse with deionized water and blot clean each time and you cap the used solution to make it air tight. Try to keep those solutions at RT (about 20 C)
For those with slow reading or non working meters, try to recondition it, it might perk up.
