Understanding PH in Hydroponics

May 30, 2023

pH plays a crucial role in achieving optimal plant growth

Understanding the significance of pH and how it affects nutrient uptake is essential for successful hydroponic cultivation. We will have a look at the  importance of pH in hydroponics, the availability of fertilisers at different pH values and the potential consequences if you neglect maintaining your pH levels.

pH and Nutrient Availability:

Making sure you maintain the right pH range in hydroponics is crucial to your success as it directly influences the availability and absorption of nutrients. 

Hydroponics generally provides greater control over nutrient availability since the plant's roots have direct access to the nutrient-rich solution. By adjusting the pH of the nutrient solution, growers can optimize the availability of vital elements.

Most plants thrive in a slightly acidic to neutral range, the general guideline for hydroponics is to have your pH set between 5.5 and 6.5. When you have your pH set between this range, nutrients such as nitrogen, phosphorus, potassium, calcium, and magnesium become readily available to the plants, which promotes healthy growth and development.Chart of the nutrients that are available to the plants at different pH levels

Maintaining pH

Here is a quick rundown on the range of products that we stock that are designed to monitor and adjust pH effectively. The first thing you will need is an instrument to check your ph and then you will need a way to adjust your pH.

PH up and down acid will enable precise pH adjustment. These products help raise or lower the pH of the nutrient solution, allowing growers to maintain the desired pH range for optimal nutrient availability.


Examples of pH monitoring instruments:

Bluelab pH Pen - Nz Made pH Pen, accurate and instant test results

Trans Instruments - pH Pen, accurate and instant test results

Flairform pH drops - Check your pH manually


pH adjustment liquids:

pH Up Acid - Used to adjust the pH up

pH Down Acid - Used to adjust the pH down

 Showing Bluelab pen in use, being calibrated to 7.0ph

Consequences of Neglecting pH Management:

Failing to monitor and adjust the pH in a hydroponics system can have detrimental effects on your plants health and productivity.

Here are a few potential consequences of having the incorrect pH values:

  1. Nutrient Imbalances: Incorrect pH levels can lead to imbalances in nutrient availability. Some nutrients may become excessively available, leading to toxicity symptoms, while others may become deficient, causing stunted growth and nutrient deficiencies.

  2. Nutrient Lockout: Extreme pH levels can result in 'nutrient lockout', where essential elements become chemically unavailable to plants, even if they are present in the nutrient solution. This can severely hinder plant growth and development.

  3. Poor Absorption Efficiency: Incorrect pH can reduce the plant's ability to absorb nutrients efficiently, leading to reduced yields, diminished quality, and increased susceptibility to pests and diseases.

  4. Altered Microbial Activity: pH influences microbial communities in the hydroponic system. Extreme pH levels can disrupt the beneficial microbial populations responsible for nutrient cycling and disease suppression, negatively impacting overall system health.



Maintaining optimal pH levels is paramount in hydroponics as it directly affects nutrient availability, absorption efficiency, and overall plant health. Through diligent pH monitoring and adjustment, you can ensure prolific plant growth and faster turnaround times in your hydroponic system.

Who knows, checking and controlling your pH might help you get closer to that ultimate harvest you have always been dreaming about!

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