So I have purchased a colorimetric pH tester but I have no idea how to test the soil 
Anyone ? What ratio of the water and of the soil ? So that the pH of the water doesn’t affect the soil ?
@kapouic
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I never PH, so I would only talk gibberish now…
Maybe @oldguy, Sheriff @gremmall, @CoyoteCody , @justgrowin could answer?
(and those are just a few of the amazing growers online at the moment… man I love this place 
)
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The slurry method allows you to get a representative sample and measurement of an entire area with just one test. Because soil pH can vary within a small area, be sure to take a representative sample. The soil should be taken from the same depth below the surface each time you test.
When using the slurry method, take soil from next to the plants, as well as some from further away. (Keep these two samples separate.) While this means a little extra work, you will get measurements that are more accurate since the amount of nutrients, types of soil, and moisture content can vary across a planted area.
All these things affect the pH of soil, so it’s important to track your pH at many points.
How to Test Soil Using the Slurry Method
- Gather some soil from the test area.
- Take the homogeneous sample and add equal parts of soil and distilled or deionized (DI) water in a 1:1 ratio. So, for 25 grams of soil you would add 25 mL of water.
- Stir the sample for 5 seconds.
- Let it sit for 15 minutes.
- Start stirring the sample again after 15 minutes, and take your measurement.
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thank you!
Tho I don’t have distilled or deionized water, could I maybe improvise a bit and mix some rain and tap water until the pH is neutral 7 and use it instead? 
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As long as its neutral you should be ok.
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Good advice 
Just be aware that with a fresh stir and particulate moving around it could skew a ppm reading .
It should settle first for that. 
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Thanks for the tag @kapouic but looks like there’s a perfect detailed answer that needs no further additions. And you’re right. This place rocks
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I agree the slurry is old and works well!
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@CoyoteCody so I have done what you have said, but when I put 5g of soil with 5ml of water I got a very bleary mixture, so when I put the drops in it, it was impossible to read what it said.
Have I done something wrong ?
I have read somewhere that ratio 5:1 is doable, what do u think ?
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You can add a little more water, but it might skew the results slightly. As long as you get a reading that is somewhere in the middle of your desired ph range you should be fine.
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Alright thanks 
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Thank you for the info! I’m also wondering, is it possible to make an independent soil test for pH, N, P, K, etc? Afraid of fertilizer upsellers.
Thanks in advance
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@hoppiefrog was saying something about npk soil testers. I believe he uses them… Thoughts Hop?
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Hoppie recommend BuildASoil tests to me but I think they are all lab tests. Link has the full paper about colorimetric tests
Accuracy Varies for Commercially Available Soil Test Kits Analyzing Nitrate–Nitrogen, Phosphorus, Potassium, and pH in: HortTechnology Volume 17 Issue 3 (2007) Results from five commercially available colorimetric soil test kits were compared with standard laboratory analyses for pH, nitrate–nitrogen (NO3), phosphorus (P2O5), and potassium (K2O) content for Salinas clay loam soil with three cropping histories. The kits ranked in accuracy (frequency of match with analytical laboratory results) in the following sequence: La Motte Soil Test Kit, Rapitest, Quick Soiltest, Nitty-Gritty, and Soil Kit at 94%, 92%, 64%, 36%, and 33%.
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I listened to a podcast recently with Tad Hussey from KIS and agronomist Kris Borgman about lab testing recently that was pretty informative. I can send you a link to it if your interested
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in a pinch they work ,but not super accurate.lab tests are accurate on the other hand .35$ tests from buildasoil tell most important levels
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