PH - logarithmic scale used to specify the acidity or alcaline

[Nanook]

The logarithmic measure of the acid-alkaline balance in water or soil is called pH.

BY ROBERT BERGMAN

The most acidic solution is pH 1. A level of pH of 7 is neutral and a pH of 14 is the most alkaline solution. For several reasons the pH has a profound effect on the cannabis plants. Various plants live under different pH levels, they have adapted to this. In hydroponic solutions marijuana grows with a low pH of 5.5. Marijuana grows best in water or soil with a pH level between 6.0-6.5 (slightly acidic). Good garden soils consist of this pH level. In this range the plants nutrients are water soluble. This means that the nutrients are available to the marijuana plants. When the pH level is outside of this range, the nutrients become less available because the nutrients won’t dissolve as well.

There is only one accurate way to adjust the pH. This is using pH test papers or a pH meter. When the pH level is outside the range, the nutrients are less available to the marijuana plant. This means that the roots don’t have access to them and now the plant indicates deficiencies, even though the nutrients may be present. If the pH level is outside the proper pH range, marijuana plants have small dark-green leafs and grow very slowly, when growing in water or soil. Check the pH (by using test strips or a pH meter) before you plant them in soil or planting mix.

If you want already pH balanced soils, use commercial potting soils and topsoil. When the plants are in the ground and the pH levels is out of range, you can still adjust the pH level. To raise alkalinity use pH-up. For the increase of acidity use pH-down. Keep checking the pH level in the soil every now and then. That’s the best way to judge if you have to stop these treatments.

Use pH-up or pH-down to keep in the range of 6.0-6.5 while using hydroponic solutions. The pH levels vary a little bit per strain. The ingredients of soluble fertilizers also affect the water pH. So adjust the pH after you added the soluble fertilizers.

[Hobbit]

Keep in mind that PH is just as important to all plants, its no more or less important for weed. Ph doesnt have anything to do with making the nutrients soluble, they are soluble regardless. PH (funnily enough few people know this) means potential hydrogen. Hydrogen due to its charge facilitates the uptake of other nutrients. Simple chemistry opposites attract. This another reason some nutrients share varying degrees of relationships with each other A good example would be the relationship of cal/mag or Nitrogen and potassium. The ph range that a plant prefers simply has to do with its specific nutrient requirements, and in that range the electrical conductivity is perfect for that plant. The preferred PH will vary across mediums as well due to CEC. Ohh and i think the author meant acidity and alkalinity, not alkaline.