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jungleexplorer

Conflicting soil reports!

Okay, I am going to start a new thread for this because the last thread was based on soil analysis that I am now doubting. I guess several years ago I bought some soil testing equipment and I completely for got about it. I stumbled upon it today and decided to try it out and the results were shocking. I did some testing with my own equipment and I got completely opposite results. Here are the two devices that I used.

1. Ferry Morse Dual Electronic Soil Tester

2. T.D.S. Digital Water Tester

I sent off two soil samples to be tested by the AgriLife Extension of Texas A&M. The reports indicated that I had High pH and low Nitrates and really low Phosphorus. Today, when I used the electronic soil tester, it came back as low pH and extremely high NPK (Nitrates, Phosphorus and Potash). Exactly the opposite of what the soil reports said.

The A&M soil reports indicated that my soil had a pH of 8.3 (averaged between the two reports). My tester indicated that my average pH after testing ten spots was 5.1 (the lowest measurement was 3.8 and the highest of 6, but all the others were around 5).

So, I thought that the device might be defective. In an attempt to prove that the device was in error, I tested twenty, 4" starter pots that I have filled with Scotts potting soil and some 3 week old starter vegetable plants. The tester showed all these pots to have almost neutral pH (6.8 to 7) and perfect levels of NPK. This is exactly what you would expect out of commercial produced and balanced potting soil, so that seemed right to me.

Still in doubt I decide to run some test on my water to get better measurements. Filling a mason jar directly from the water in my Greenhouse, I submersed the tester probes in it. The results were a pH of 5.8 and NPK of extremely high. I know that I have hard water, but until today, I did not know how high. Using my T.D.S. Digital water tester I tested the water from the greenhouse. 824 PPM! Not that's hard buddy! It's amazing that it is still liquid.

Still in doubt, I got a glass of water from my drinking Watt's 5 stage R.O. system. The tester show a pH of 7 and just a tiny amount of NPK. Concerned that the tester was wrong for showing some menirals in the water that should not be there after going through an R.O. system, I tested the R.O. water with the water tester and it showed 66 PPM, (so it is time to service my R.O. system which I have been neglecting to do).

Still in doubt about the accuracy of my equipment I went to the store and bought a bottle of distilled water. This would be the final test. If it showed a neutral pH of 7 and zero minerals then I would know that my equipment was right on. The soil tester showed the distilled water to have a pH of 7 and not a trace of any NPK. The water tester showed that the water had, 0 PPM.

Okay so I know that both of my devices are working perfectly. But, how can this be? I am conflicted here on what the believe? It just seems illogical that some hand held testers can be more accurate then the advanced A&M soil testing lab. I mean, slightly different results would be one thing, but completely opposite results! What's going on here?

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