Papa Jim

That don't sound like it's working correctly. You should be seeing larger reading differences between stuff. Make sure your probe tips are clean. Use one of those pot scouring pads to clean them up. Then try it again and leave it in the material for a minute or two to settle it out.

As far as a calibrate kit, I haven't seen any. The best I can think of to find a calibrate kit would be at a swimming pool store like 'Pinch A Penny'. I know people have to keep their swimming pool water neutral, so try them.

I know my meter shows a big difference between my acid loving plants like blueberries from the regular garden soils.

Lou

Clean the aluminum part of the probe with scotch-brite, not the tips. Soak the probes in distilled vinegar for 4-5 minutes and rinse in clean water Then back into the vinegar. It should read ph 3 +/- .5 after a min or two. My experience with those cheap meters from the garden centers, they don't work for very long.
john

I did the same thing, got a cheapie at HD and finally took it back.... then I went to a meeting of the Heritage Rose Society in Lakeland at Fla. Southern College, and a lady brought a REAL meter..... says it doesn't need calibrating... so I looked it up and it costs abt. $95.... but she has 900 ( nine hundred ) roses and says they do so much better if she keeps the PH at a certain level... she had a Kelway meter and they can be ordered from a firm right here in Fla., also Rosemania Roses carries them... I don't know if $95. is in my price-range, but I'm sure it would be far more accurate than the cheapie from HD...............sally

I agree with Johnjsr on the cleaning of the probes You can also check the accuracy of the probe by using plain black coffee which has a almost perfect PH of 5.

Thanks johnjsr for the 3.

Thanks bamboo rabbit for the 5.

I can use that info to calibrate it or chunk it.

Papa Jim

I scoured the probe good and got a 3.7 on vinegar. I'll try it on my coffee tomorrow morning. For less tha $10 I guess I can't complain.

Bummer! Coffee Black coffee came in at 6.6. I think I'll upgrade.

Papa Jim

A ph meter is really just a volt meter that has a scale that reads voltage as ph. Cleaning the aluminum part of the probe is essential every time you use it. Aluminum starts to oxidize just as soon as you clean it and the aluminum oxide that forms is an insulator. Don't clean the tip with the same piece of sb it will contaminate it and distort the reading you get.
john

papajim,

Did you clean off the probes again before you checked out the coffee?? They need to be clean before you take a first reading. If I take multiple readings one after the other then I just rinse it off and wipe then test the next pot. Usually the abrasion of the dirt will keep it clean while you are taking the readings, but If it is a next day or more reading then it has to be cleaned all over again before use. The aluminum part of the probe makes a very thin coating in just a few hours that you cannot see but it will screw up your readings. Don't go bananas and wear out the aluminum cleaning it, all you are trying to do is remove that microscopic coating that aluminum makes when exposed to air.

Lou

Lou, what make meter do you have ? is it the Kelway? the rose expert seems to think it is the best, and says it needs no calibrating, she said you just stick it in the dirt for a minute, read it then put it away... it comes in it's own little leather case, she handed it around at the meeting..... I was impressed.... but it is pricey.... thanx, sally

Sally,

My meter is a 3 way meter that I bought many years ago up in New Hampshire and it is still working great.

1. It tests for how much light is getting to the plant.

2. It tests for the moisture content of the soil.

3. It tests for the PH of the soil.

I have no idea the name of it as the many years of use has now worn the name clean off. I cannot recall what I paid for it, or whether it was pricey or not. I would guess it is 30 years or more old.

Lou