Quote Originally Posted by newmangreen
ok guys i see some signs of trouble. The edges of the leaves on some of the girls are curling up and getting pretty dry and scaly looking. I tested the runoff Ph and its 5, so that could be it. The Ph before watering is 6 though which is pretty good. Are there any ways of raising it on the fly if i need to? Or maybe anything else it could be?
http://boards.cannabis.com/plant-pro...hy-how-do.html

Quote Originally Posted by stinkyattic
First, measure the pH of your tap water and record it. As an example, let's say that it is 7.0, exactly neutral.

If you have a meter, simply stick the electrode in the water and read.

Let's say that your runoff comes out at 6.5. How did that happen? The water passed through a more acidic matrix and dropped its pH. You can assume that your true soil pH is a couple tenths of a pH point lower than the runoff in this case- I'd assume about a 6.2. If it comes out HIGHER, just go in the opposite direction. If it came out 7.5, you can assume that you need to drop down from about 7.8.

You want around 6.0-6.5 for a soilless mix, or 6.3-6.8 for soil.
^^By this logic, your soil would around 4.7... Plus if the soil has ferts in it already, that could burn them up also. I'd go check out to see if your ph tester was calibrated correctly before messing with the ph and possibly introducing a new problem. If it's a color-coded test, then the water has to be clear for the test to be accurate.