The pH of solutions used for fertilizing or supplementing plants is critical and should be checked frequently to maintain a fairly neutral balance. Variations toward acidity or basic solutions will impact how well a plant absorbs nutrients.
Acceptable pH ranges differ among plant types, growing mediums, and hydroponic systems. Generally desirable readings range from 5.5 (slightly acid) to 7.0 (neutral). It is usually best to maintain a pH value of 6.5 as nutrients are absorbed best when pH is 6.0 to 7.0.
Use pH up and down adjusters carefully and mix in slowly and completely. Fertilizers, when added will usually lower the solutions pH value. Most of the time, as solutions are used by plants, the pH will raise, and additions of fertilizer, or a pH down adjuster will be needed. It is preferable to adjust water pH before adding fertilizer, once you are familiar with what adjustments will be required. Solution pH can be determined either by a reagent color comparison method or with an electronic test meter. |