The process of podzolization usually occurs under low pH values.

At the same time, the pH value of the water needs to be above 8,0 (slightly alkaline).

Phenolphthalein changes color over a range of pH values between 8 and 10.

The culture is kept under lighting with temperature and pH value held constant.

It will change from red to yellow color when the pH value decreases.

Therefore pH values on the different scales cannot be compared directly.

Thus, measured pH values will lie mostly in the range 0 to 14.

The pH value of a concentrated solution will lie between 5 and 6.

Variation in growth rate across pH values of 4, 7 and 9 was insignificant.