I've been growing for many years but I am totally new to pH and tbh I don't understand it at all.
To make matters worse, I cannot seem to accurately measure it no matter which method I use.
For example, I recently purchased a pH test kit where you fill up a test tube half way with the water you want to test, put 3-5 drops of testing liquid in the test tube, then compare the color it makes with the color on a chart. That's what I was working with today.
I needed to water my plants today, so I tested the pH of the water without nutes, the water with the nutes, and the runoff water. The tap water tested at 7.0, the nute-water tested at 6.0 and the runoff tested at 4.5. This made me think I had a too low pH problem, perhaps causing nutrient antagonists, so I decided to flush (plants are in 3gal pots).
After flushing with three gallons of 7.0 pH tap water the runoff tested at 5.0 pH. After six gallons it tested at 5.5 pH. After nine, 6.0 pH and after twelve gallons per three gallon pot the runoff water was finally testing at 6.5 pH. This is the ideal pH for dirt according to the nutrient chart.
I then watered with 6.0 pH nute-water and put the plants back in the cab.
Now, here's where things go off the rails. After each 3gal flush, I saved a sample of the runoff water. So I have glasses with runoff in them after 3gal flush, 6gal flush, 9gal flush and 12gal flush. I just tested them again, now six hours after the flush, and they now ALL test 7.0 pH.
The only runoff sample that tests the same is the first one I took before the flush. It still tests at 4.5 pH.
What is going on here? How can water that was testing at 5.0 PH six hours ago and just sitting in a glass, with nothing added or removed from it, baseify itself 100x and now be testing at 7.0 pH?
That's got to be either a measurement error (my fault) or instrument error (the test kit's fault) because such data just doesn't seem plausible to me, unless I'm missing something?
The only thing I can think of is I covered the first sample (the one testing at 4.5 pH) with plastic wrap but didn't cover any of the other samples (the ones now testing at 7.0 pH that were testing at 5.0, 5.5, 6.0 and 6.5 respectively). The glasses are just sitting on the kitchen counter, no visible dust or contamination. I wouldn't think so, but could that possibly have any effect, and what do you think is the best, most reliable way to measure pH?
Thank you.
To make matters worse, I cannot seem to accurately measure it no matter which method I use.
For example, I recently purchased a pH test kit where you fill up a test tube half way with the water you want to test, put 3-5 drops of testing liquid in the test tube, then compare the color it makes with the color on a chart. That's what I was working with today.
I needed to water my plants today, so I tested the pH of the water without nutes, the water with the nutes, and the runoff water. The tap water tested at 7.0, the nute-water tested at 6.0 and the runoff tested at 4.5. This made me think I had a too low pH problem, perhaps causing nutrient antagonists, so I decided to flush (plants are in 3gal pots).
After flushing with three gallons of 7.0 pH tap water the runoff tested at 5.0 pH. After six gallons it tested at 5.5 pH. After nine, 6.0 pH and after twelve gallons per three gallon pot the runoff water was finally testing at 6.5 pH. This is the ideal pH for dirt according to the nutrient chart.
I then watered with 6.0 pH nute-water and put the plants back in the cab.
Now, here's where things go off the rails. After each 3gal flush, I saved a sample of the runoff water. So I have glasses with runoff in them after 3gal flush, 6gal flush, 9gal flush and 12gal flush. I just tested them again, now six hours after the flush, and they now ALL test 7.0 pH.
The only runoff sample that tests the same is the first one I took before the flush. It still tests at 4.5 pH.
What is going on here? How can water that was testing at 5.0 PH six hours ago and just sitting in a glass, with nothing added or removed from it, baseify itself 100x and now be testing at 7.0 pH?
That's got to be either a measurement error (my fault) or instrument error (the test kit's fault) because such data just doesn't seem plausible to me, unless I'm missing something?
The only thing I can think of is I covered the first sample (the one testing at 4.5 pH) with plastic wrap but didn't cover any of the other samples (the ones now testing at 7.0 pH that were testing at 5.0, 5.5, 6.0 and 6.5 respectively). The glasses are just sitting on the kitchen counter, no visible dust or contamination. I wouldn't think so, but could that possibly have any effect, and what do you think is the best, most reliable way to measure pH?
Thank you.
