You may want your University of Tennessee USDA Cooperative Extension Service do a soil test also and compare the results. Based on past experience this meter is not worth the money you invested and one of the major problems is even if the soil pH test is close it does not tell you why the pH is where its at and you need to know that before you can correct it, if that is needed. Most people that have had these have found they report the same pH when testing soil, vinegar, and baking soda.

Hope I'm not too late...

While I agree with getting a soil test, I have used the exact model you are talking about for around 5 years now. I also have a 4-way model (pH, light, fertility, moisture.)

Of the two models, I've had great success with the model you got. While you can't be sure it's exactly true readings, you can see major differences.

For example: My compost was about 7.0 and my container mix recorded about 6.0. When I mixed up a batch of container mix that incorporated compost (maybe 25% or so), when I retested my mix it was around 6.2-6.3. The same compost was taken from my pumpkin patch, at a depth of about 6" and sent to Penn State for a professional soil test, which included many add-ons like organic matter content, CEC, calcium, magnesium, etc.

My results back from Penn State for pH was 7.0. Coincidental?

While I can't say that the meters are all accurate, or the amount of accuracy, I can say that mine was pretty accurate and responsive, whether in pH or Fertility mode.

As for the fertility test, the readings divided the scale into three parts: too low, ideal, and too high (I think that was the wording, or maybe Very low & Very high.) Sticking the meter as directed into various soils, composts, mixes, etc, did indeed show different readings of fertility. For example, the ProMix BX was showing too low, the compost was on the higher end of ideal, etc. Even spraying a potted plant's soilmix with water, testing fertility, then spraying the same plant's soil with Neptune's & Maxicrop (and retesting) showed a significant needle movement--from the lower end of Ideal, up to the higher end of Ideal--maybe a quarter inch of sweep on the scale.

So this model I WOULD recommend. Now, as for the 4-way model, the pH results were slightly less than the Rapitest brand 2-way model (the Rapitest 2-way requires a battery, the 4-way is a different brand & requires no battery.) Furthermore, a year or two later, the 4-way seems to not really give different readings anymore, not on pH, fertility, etc!

Just a note, I should say that I stumbled onto this thread when I was googling for the "Rapitest Electronic Soil Tester" since the 4-way off brand doesn't do anything and I can't find my Rapitest model. Some of the reviews I've read on Amazon that support what you said about it not reading differently for things like vinegar & baking soda are for a DIFFERENT BRAND/MODEL of pH meter, NOT this specific one.

Hope this helps.

Mark
(from the tomato forum)

I've had fair luck with the kind of tester you're
talking about for ph but I wouldn't put much stock
in "fertility levels" or anything like that. I used
a Rapid Test for ph to get my blueberries sufficiently
acidic and for that kind of thing I thing these testers
work pretty well. Litmus strips are another option.

Mark (korney19),

Hi ... Is this the soil tester that works for you? (see link below).

Does anyone else have a recommendation of an inexpensive one that works, or how to care for it to keep it working?

Mostthings grow pretty good in our yard because of our raised beds and frequent additions of compost, and all the basic good gardening practices, but I think I'd like to push my blueberry and strawberry beds towards the acid side and would like a clue to see if it's working, without paying for a soil test every few months.

Thanks,
Ron

Here is a link that might be useful: Rapitest Mini pH-Moisture Tester

Ron:
You do not need to test soil every few months.
A good, reliable soil test every few years is all that is needed to maintain a good, healthy soil.
Spending money on a home test kit that is often very unreliable is a waste of your time, energy, and money.
Talk with the people at your local office of your state university USDA Cooeprative Extension Service (a service you pay for whether you uses it or not), people that know more about your soil than you ever will.