And regarding PB saying that "any nutrient solution that is applied will go to the pH of the media over time," it doesn't take soil long at all to balance the pH of the water you pour in. The proof is that slurry testing is the standard for pH testing soil.
For example, Hanna Instruments (they make lab quality pH meters) recommends 30 minutes before testing the slurry. Another industrial meter company (Cole-Parmer) recommends an hour.
Here's how it works in practice: I take the substrate and add the same amount of distilled water (pH 7) to make a muddy slurry, which is a lot more water than we retain in our pots. Within an hour, the slurry will be the pH of the medium, not the water. That's how quickly ProMix/soil buffer water pH.
For example, Hanna Instruments (they make lab quality pH meters) recommends 30 minutes before testing the slurry. Another industrial meter company (Cole-Parmer) recommends an hour.
Here's how it works in practice: I take the substrate and add the same amount of distilled water (pH 7) to make a muddy slurry, which is a lot more water than we retain in our pots. Within an hour, the slurry will be the pH of the medium, not the water. That's how quickly ProMix/soil buffer water pH.
to VG Jr.
