PrecisionpH Adjustment Solutions for Hydroponics

Most people are familiar with pH("potential hydrogen") as an indicator of how acid or alkaline asolution is. The pH scale ranges from 0 pH (very acidic) to 14 pH (highlyalkaline). Pure water, at 7 pH, is neutral--neither acidic or alkaline.Maintaining proper pH is critical, whether growing in soil or hydroponically.Plants absorb each nutrient element only within a certain pH range, and becausethis range is different for different nutrients, there is only a relativelysmall pH range in which all nutrients are available.

Plants can generally survive within a pHrange of 5.0 - 7.5. Below 5.0 pH there is a danger of burning and destroying thesensitive root tissues, while at pH levels of 7.0 and above some nutrients mayprecipitate out of solution and become unavailable to the plants. The optimumlevel is about 6.3 or 6.5 pH, with anything in the range of 6.0 - 7.0 beingacceptable. Unless an automated controller is being used, the pH level should bemanually tested and corrected daily.

The natural tendency in hydroponicssystems is for the pH level to rise as plants use up nutrient. This must becorrected by use of an adjusting "pH Lower" (acidic) solution. Thereare also alkali, or "pH Raise" solutions available to correct a pHlevel that has become too low. An adjusting solution (either acid or alkali)should not be introduced into the system at full strength because this can lockup (precipitate) nutrients, in addition to being a shock to the system. Ideally,the adjuster should be diluted to about 0.001 strength (0.1% solution) before itis introduced into the system. For example, if you begin with "fullstrength" (75% solution) of phosphoric acid, you should dilute one partacid to about 750 parts of fresh water. Similarly, acid (or alkali) at 8%strength would ideally be diluted one part adjuster to 80 parts fresh water.

Evolution Solution ready-to-use pH Raiseand Lower Solutions are pre-mixed and are available from your favoritehydroponics retailer in the following sizes:

• 500 ml
  

• 2 litre
  

Bulk sizes available. Please enquire.

HOME