Indoor accurate ph readings for soil?

[GoTgReEn]

Hey everyone, this subject has been on my brain all day.
So basically i have been searching internet to find the most accurate way of measuring PH of my soil and i came across these two methods;



*Method One-*
1. Measure the pH of Input (water or water/nutrient mix) you are planning to use.
2. Water Plants
3. Measure the pH of the Runoff.
4. Soil pH = pH Input + pH Runoff divided by 2

Ex. pH Input (water or nutrient mix) (measured 7) + pH Runoff (measured 6.0)/2 = 6.5 Soil pH; basically saying that Soil pH is the mean or 'mid point' between the Input and Runoff pHs.


*Method Two*
1. Measure the pH of Input (water or water/nutrient mix) you are planning to use.
2. Water Plants
3. Measure the pH of the Runoff.
4. Runoff pH=Soil pH. This assumes that you would adjust the pH of your initial Input (water or water/nutrient mix) up or down so that the resulting Runoff/Soil pH is within the 6.2-6.8 Sweet Spot pH range.

Ex: Input (water or water/nutrients) has a pH of 7, the Runoff measures 5.8. If I wanted the Runoff to pH at 6.5, this would then mean that the Input's pH would need to be
*Method Two*
Soil pH = Runoff pH*


Iv been using method 2! As i assume that's the PH at root zone.

Can anyone clarify this please????

 

[gooseberry]

when soil scientists measure soil pH they do it on a slurry prepared using a defined quantity of soil and a defined quantity of water (or electrolyte solution). I suspect that what you really want to know is the pH of the soil pore water. Any measuremet will only be as good as your determination. I think that generally measuring soil pH is operationally defined, so consistency of your method is probably quite critical, and comparison with other peoples methods somewhat difficult.

I think I would be inclined to use a slurry, it's probably as close to the pore water a you will get, and this is what the plant will be experiencing. Making it up wth your nutrient solution might be most realistsic.

 

[Duck Commander]

I use method 1 and always split the differance mine goes in at 6.7 and my run off is 6.4 so my actual must be 6.5- 6.6

 

[GoTgReEn]

Sup gooseberry iv read this also, thanks for the input but im no Scientist man! :smoke:

 

[GoTgReEn]

Si that does seem a good way

 

[gooseberry]

I think that the advantage with using a slurry is that the solid phases in the soil have some buffering capacity, and if you separate the solids from the pore water then this buffering capacity won't contribute to your measurement (the effect might be fairly small though, I suppose it depends on your soil)

 

[hereb4]

View attachment 126167View attachment 126169View attachment 126168I just checked...my soil tester (accurate 8) reads 6.5
water in was...6.4
runoff is...7.1
liquids are tested with a nutradrip tri-meter.