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How to read this soil test kit?

Posted: Tue Mar 03, 2015 7:00 pm
by JT101
Hi everyone

I have one of the Testwest Soil Testing Kits, but I don't understand the result.

I followed the instructions for the pH test using clear liquid that I got once the solid particles had settled, which infact took about 2 days.

The colour chart supplied stops at a green 7.5. Mine is a very dark turquoise blue. So I went on the web to find a pH colour chart, but there are so many, and lots are different. On one chart I would say it was 11, and on another is was 7.5

Secondly, I noticed on all four samples, the white pH powder I added dropped to the bottom of the sample. I had given it a good shake for 30 seconds, and allowed to sit for 5 minutes. I shook it again and the same thing happened.

Now I've slept on it and had time to think, it looks totally like the powder didn't mix with the reagent droplets I put in which were a dark blue. well it stayed mixed for a few mins then dropped out of the solution. The final solution looks like the coloured water before I added the powder.

Is this normal? I assume sort of chemical reaction is supposed to take place

Anyone got any ideas. I'm attaching a photo of the sample and chart

And are soil pH charts somehow different to others?

Re: How to read this soil test kit?

Posted: Wed Mar 04, 2015 5:40 pm
by diggernotdreamer
I bought one of these test kits, they are rubbish, I even contacted the company selling them and complained to no avail, I tested everything, I even tested my own urine and all the tests were the same colour, I have now got myself a new ph meter which I know isn't 100 per cent accurate, but it is better than this. You have to pay a bit more to get a decent kit

Re: How to read this soil test kit?

Posted: Thu Mar 05, 2015 6:22 pm
by berry
just pick up a packet of litmus paper -make sure it does the full range of ph from 1-14 not the simple acid/alkali stuff- its cheaper and easier to use than soil testing kits. you can get them from lab supply places, photographic suppliers even that big web store that doesnt pay its tax :? .

I had a load for my some darkroom work and gave it a go with my soil. pretty accurate!

Re: How to read this soil test kit?

Posted: Thu Mar 05, 2015 7:27 pm
by Odsox
Very good advice
You can also get a very good range (pH that is) of litmus test strips from home brew wine equipment shops.
You could also test your own kit by substituting the water for vinegar, which should be about 2.5. If it still comes out turquoise you'll know for certain it's a crap kit.

Re: How to read this soil test kit?

Posted: Thu Mar 05, 2015 9:30 pm
by diggernotdreamer
Thanks for that, I will buy the paper, I did not know you could buy them with such a large ph range

Re: How to read this soil test kit?

Posted: Fri Mar 06, 2015 10:22 am
by berry
pretty easy to get hold of just make sure they are from a UK supplier - more accurate. theres videos available that show you how to do the soil test and other cool experiments you can do. esp things like how to neutralise acids/alkalis. ah I'm waffling.