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I was told to measure the pH of my soil to help identify some of the symptoms on my vegetable plants. Does anyone have recommendations of a device I can purchase to measure soil pH?

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The best way is to get a soil test. If you can find a COOPERATIVE EXTENSION SERVICE via the closest University, it is cheap and possibly free. Otherwise there are cheap tests like the ones used for HOT TUBS. There are also these pronged things that seem to work well. I own a very expensive pH tester and test these other cheap LOWES or HOME DEPOT pH testers. They have impressed me. I always use at least two forms of testers. Need to have moist soil and test multiple places. Potatoes, blueberries need acidic soil; 5.0 to 5.9. Other plants need more alkaline soil; 6.0-7.3.

pH is one of the best ways to separate real gardeners from wannabees! With this knowledge you can plant alkaline loving plants together and the acid loving plants together. To plant any acid loving plants next to concrete you will find is nuts. But one CAN change the pH of soils, slightly. Harder to make soils more acidic. Always do in stages, test again, add lime for alkaline (going up on the scale) and add sulfur (going down the scale towards acid)...go SLOWLY. Takes weeks to months to see change. Keep this in mind when you test.

  • for clarification, are you saying that you were impressed with the ph testers available at lowes or home depot? – JStorage Jul 12 '16 at 23:54
  • Acidifying the soil with peat moss (which has a pH of approximately 4.0) is probably safer and faster than using sulfur. Plus, the organic matter helps. – Shule Jul 13 '16 at 1:07
  • Peat moss is what we used to help balance all the wood ash that was scattered in our growing area, this year (which had plants suffering from nitrogen deficiency, stunting, etc.) The plants are growing much bigger and faster this year. Wood ash is high in calcium and can raise the pH. – Shule Jul 13 '16 at 1:12
  • Yes but 'this much' of peat moss to nullify 'this much' of calcium is way too iffy. Wood ash a bit up and peat moss a bit or more down. This is just too iffy after putting in so much sweat equity and every season being a short time to WIN. I fertilize as the plants need it. Takes a bit to get to the point where one can read what a plant needs. I am rudimentary. But watering, fertilizing on a schedule is non-sense. To do something that sorta makes sense in combination with something else that sorta makes sense is also non-sense. My opinion of course! grins. Did you test your soil? – stormy Jul 14 '16 at 1:15
  • JStorage, that is why I have three ways to test pH. I've got an expensive pH meter and two from lowes, or wherever. The Lowes or Home Depot cheapie pH meters have actually performed well. Surprisingly. Best way is to get a professional soil test once per year. Blueberries, potatoes...need such acid soils, versus most of the other crops. Really cuts down on areas for rotation. When I see a plant in trouble the first thing I do is test the pH. You can fertilize like crazy and if the pH is wrong the plants will not be able to use the chemicals. Same with microbiology. – stormy Jul 14 '16 at 1:27
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Measuring the pH of soil is cheap and super easy (I do this often).

  1. Get a (plastic) bowl.
  2. Put a sample of soil in it.
  3. Add distilled (not rain or tap) water and mix it to the consistency of a milk shake.
  4. Wait 30-60 minutes, until the soil settles and you have mostly water on top.
  5. Test the pH of the water/supernatant with a pH meter or litmus strip(s).

Trouble shooting tip: If you added too much water, add more soil.

Question: How do I know this is accurate?

Answer: pH is logarithmic, so you can't go very wrong. In other words if you have a 100 ml of solution with pH of 6.60, and you add 100 ml of distilled water to that, the pH of the 200 ml solution will be 6.71. So, being off by less than double the amount of water will not mess up your results too much.

Question: why do I have to use distilled water?

Answer: The pH of rain water is about 5.6, and the pH of tap water should be between 6.5 and 9.5... and it often is.

Question: Where do I get litmus strips or a pH meter?

Answer: Online (like eBay) will work; or the pharmacy, aquarium, pool, or lawn and garden section of many box stores (like walmart) should also carry them. There are (probably) thousands of pH strip products... they will all work for soil testing.

Shopping tips: For testing soil, any cheap pH strip (within range) should be good enough; look for strips that have good color definition around pH 5 - 9. Pool pH strips might be more expensive and specific for the higher range (pH 7 - 10) and they might include other/unnecessary tests. On the other hand, if you have a pool, then having dual purpose strips makes sense. Otherwise, I would probably opt for something like urine or aquarium strips (which are usually meant to read pH in the range of 4 to 10).

For pH meters, look for a model with straightforward calibration techniques. Always check the product reviews before spending your grocery money.

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  • How do you know if you've added too much water versus soil? Why that amount of water to test the soil's pH? Otherwise, we are testing the pH of the water. pH testers are best found in the marijuana grower stores. I am not kidding. Marijuana growers are MOTIVATED to learn quickly and pay attention to their crops. Those stores have the best pH meters, pots, soils, pH up, pH down, lights and the staff are usually far more knowledgeable. I always have at least 2 or 3 ways to test pH in between soil tests. Cheap cheap cheap, coop extension services nearest university! – stormy Jul 14 '16 at 1:17
  • @stormy pH is a measure of H+ ions in water. Actually, the best pH meter is colorimetric titration, followed by litmus paper. But if you really want to use electronic meters, Thermo Scientific makes the best pH meters on this planet (for a mere 1-2 thousand dollars). But Hanna meters (about $50) are okay for general tests. I often use a plug in model from Corning, but, I actually prefer litmus paper because they are more reliable and accurate than electronic meters, and the price is only about $3 per 100 test strips and I've found that a book of strips lasts longer than batteries. – Ben Welborn Jul 14 '16 at 17:33
  • I'll have to go out and find the maker of my pH meter. Cost me 2 or 3 decades ago $350. I've lost the cleaning pieces of plastic to help reset it and have been using those grocery plastic bags to reset and seems to work. They use those at the cashier's register to make funked up electronic strips on credit cards. Do you know anything about this plastic 'reset' for the electronic meters? Do they make litmus paper for testing soil pH? And where do you get yours? I really got into testing our hot tub water with strips and I loved how consistent they were. Same thing? – stormy Jul 14 '16 at 18:26
  • @stormy Regarding plastic and plastic bags to clean and reset meters- I do and I don't know... actually the Hanna meter (that I used to have) had a plastic dohickey for cleaning it... but it's long gone now. I'm familiar with the credit card - bag method, but I've always used buffers to calibrate my meter(s). – Ben Welborn Jul 14 '16 at 19:33
  • @stormy About the strips... there are so many kinds of pH test strips, I have no doubt that somebody out there is trying to sell some for soil testing, but regular old pH strips should work perfectly well. I edited my answer to include a little more detail about strips. You should be able to use pool strips so long as they have good range and acceptable precision at your pH. If you can barely tell the difference between pH 5 and pH 6, that's not very good... but it will give you an idea of the range. – Ben Welborn Jul 14 '16 at 20:29

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