In hydroponics, pH is a crucial factor that directly affects plant health, nutrient availability, and overall system efficiency. Understanding and managing pH levels in your hydroponic system is essential for optimal plant growth and yield.
What is pH?
pH stands for “potential of Hydrogen” and is a scale used to specify the acidity or basicity (alkalinity) of an aqueous solution. It is calculated as the negative logarithm of the hydrogen ion concentration in a solution. pH is a measure of how acidic or alkaline a solution is, ranging from 0 to 14.
In hydroponics, the pH level of the nutrient solution plays a vital role in how well plants can absorb essential nutrients.
pH 7 is neutral, meaning the concentration of hydrogen ions (H⁺) is equal to the concentration of hydroxide ions (OH⁻).
pH less than 7, indicates an acidic solution, where the concentration of hydrogen ions is higher than that of hydroxide ions.
pH greater than 7, indicates a basic or alkaline solution, where the concentration of hydroxide ions is higher than that of hydrogen ions.
When water is recirculation in our reservoirs, pH drastically keeps increase or decrease. Plants absorbs the nutrients that is in the form of ions: it takes one +ve ion gives back one +ve ion same as –ve ion.
Why pH is increase?
Nitrate is anion, it is most important for plant root zone. When plant takes nitrate anion it gives out as hydroxide ions (oH-)
When the plant takes more no of nitrate anions, it will release the same no of hydroxide ions (OH-).Hence pH will increase.
Why pH is decrease?
When the plants are absorbing calcium and potassium and magnesium (cation) +ve ions, so plant will release the same no of hydrogen ions (H+). Hence pH will decrease
pH up & down:
pH down use phosphoric acid or Nitric acid (don’t go for hydrochloric acid)
pH up uses potassium hydroxide
How do you measure pH in water?
Why pH Matters in Hydroponics?
Nutrient Availability:
pH levels directly influence the availability of essential nutrients in the hydroponic solution. Most nutrients that plants need, such as nitrogen, phosphorus, and potassium, are most readily available to plants when the pH is within a specific range. For most hydroponic systems, the ideal pH range is between 5.5 and 6.5.
Optimal Growth and Health:
Consistently maintaining the correct pH level ensures that plants can absorb nutrients efficiently, leading to healthier growth and higher yields. When the pH is out of range, plants may exhibit symptoms like yellowing leaves, stunted growth, or poor root development, which can significantly impact the success of the hydroponic system.
Preventing Nutrient Lockout:
Nutrient lockout occurs when plants are unable to absorb nutrients due to inappropriate pH levels, even if those nutrients are present in the solution. This can cause plants to display symptoms of deficiency despite an adequate nutrient supply.
System Stability:
Maintaining a stable pH in a hydroponic system also contributes to overall system stability. Frequent pH fluctuations can stress plants and disrupt their ability to absorb nutrients. Regular monitoring and adjustments help keep the system in balance, promoting a healthy growing environment.
