There seems to be plenty of room for debating which method will give you the “correct” pH reading. In my opinion measuring the soil pH about 2” down and toward the outside of the pot is the better method. I’m sure there are differing opinions out there.
Let’s discuss! The more empirical evidence the better!
I think a good way of determining if your ph is too high or too low is to take a ph reading of whats going in and also a reading of your runoff.
Suppose there is a big difference between the two. Do you choose one over the other or do you average the two?
As far as I understanding you will end up with incorrect pH when averaging pH readings from separate probes without first converting to H+ concentration and then finding the mean. With that being considered you would either be forced to do some more serious math or, if you hate math, choose between testing runoff or soil.
What going in is what i measure when i measure, or run off if something is a muck.
As far as getting an average i would say you get a better understanding of what your roots are getting is to ph the runoff. Personally i dont check ph at all. I probably should test the ph of my input solution, which is usually a compost tea but i havent in a while. I think strong genetics have the biggest influence on how your plants turn out. But thats not what this conversation is about.
@Mr.Sparkle Definitely agree that everybody should be measuring the pH of their solution before feeding. Not doing so is a recipe for disaster.
Had to edit this for @hewhocoruptz. Certain organic methods are much less prone to pH issues. However, one of the first steps in troubleshooting a plant problem is verifying pH. And common sense says that the area around the roots would be most effected by pH. Question is, do you test the soil near the roots or the runoff to get the most accurate reading of pH?
Seeing as ive never used an accurate soil ph meter i would measure the runoff.
I measure the feeding pH and EC and then measure the pH and EC of the runoff to see if anything needs to be tweaked. My meter probe only measures liquid right now but in the near future I would like to get a soil probe so I can also know the pH of the root zone. Sometimes the two can be very different and problems can arise.
Anyone happen to have one of these yet? Would love to know if it’s worthwhile.
https://www.getbluelab.com/shop/By+Category/Replacement+Probes/LeappHProbe-.html
@neogitus When measuring soil pH, mix or shake the soil sample with equal parts pH neutral water. Let it sit for 30 minutes or so to settle and then take your reading. The probe you linked is capable of taking measurements this way, although it recommends taking 20g soil sample at 6” depth mixed with 150ml of pH neutral water. I don’t think 6” is totally necessary, 2” or so should be fine.
@hewhocoruptz There are plenty of accurate pH meters. Check the technical specifications for the one above and this pen as well. +-0.1pH is accurate enough if you ask me.
Thanks dude… I used this method and it seemed to work fine.
I used a Hanna meter, which are pricey but effective.
