Happy Urban Dirt

Maintaining proper pH levels in hydroponic systems is crucial to plant health and growth. One common challenge growers face is pH drift. In this article, we’ll take a look at what pH drift is, why it occurs, and how it affects hydroponic systems. We’ll also discuss solutions to mitigate the problem and how they work.

What is pH drift?

pH drift occurs when the pH level of the nutrient solution used to feed plants changes over time, usually within a few hours.

This is common in recirculating hydroponic systems such as DWC, NFT, Ebb and Flow, RDWC and similar.

pH drift can occur in two ways: pH can escalate (for example from 6.0 to 7.0) or decrease (for example from 6.0 to 5.0) in a compact period of time. Sometimes pH can even fluctuate up and down in a compact period of time, especially without pH controller.

This makes it tough for plants to absorb necessary nutrients.

Why does pH fluctuate?

Several factors influence pH changes in hydroponic systems:

• Nutrient depletion: As plants absorb nutrients, the composition of the nutrient solution changes, which can cause pH levels to fluctuate.

• Water changes: In systems where vast volumes of water are frequently added, up-to-date water can change the pH of the water over time.

• Microbiological Activity: Beneficial and harmful microorganisms in a nutrient solution can produce by-products that affect pH.

How does using reverse osmosis (RO) water in hydroponic systems affect pH change?

Using reverse osmosis (RO) water in hydroponic systems can affect pH drift because RO water does not contain minerals that facilitate stabilize pH levels. In regular water, minerals such as bicarbonates act as buffers, preventing sudden pH changes.

However, RO water is filtered of minerals and has no buffers, which makes the pH more prone to fluctuations when nutrients are added. This can cause the pH to drift over time, which can stress plants. To prevent this, growers can mix a diminutive amount of regular water with the RO water. This step can facilitate maintain a stable pH, ensuring vigorous plant growth.

Does the type of hydroponic method affect pH change?

Yes, the type of hydroponic growing method can affect pH drift. In recirculating systems, the water is in constant contact with the plant roots or growing medium.

As plants absorb nutrients, the chemistry of the runoff water changes. When this changed water returns to the main reservoir, it can change the overall pH of the system. This makes pH management more tough.

The most popular recirculating hydroponic systems include Deep Water Culture (DWC), Nutrient Film Technique (NFT), Recirculating Deep Water Culture (RDWC), and Ebb and Flow systems.

Does using a float valve in my water make-up system cause the pH to slowly rise?

Yes, using a float valve in a hydroponic system to top off can cause the pH to slowly rise. When a float valve adds water to the system to maintain the water level, it is usually adding plain water without nutrients. This dilutes the nutrient solution, often leading to an escalate in pH over time.

The added water will usually have a higher pH, usually between 7.5 and 8, compared to the nutrient solution, where most growers maintain a pH of 5.8 to 6.2. Adding higher pH water over time will gradually escalate the overall pH of the solution.

Regularly monitoring and adjusting pH can facilitate solve this problem by ensuring optimal conditions for plant growth.

How does increasing pH affect my plants?

When the pH of water in a hydroponic system increases, it can negatively affect plants by limiting the availability of nutrients.

At higher pH levels, necessary nutrients such as iron, manganese, and phosphorus become less soluble and less available to plants. This can lead to nutrient deficiencies, even if these nutrients are present in solution.

Symptoms of nutrient deficiencies include yellowing leaves, impoverished growth, and reduced yields. Therefore, maintaining pH in the optimal range (usually 5.8 to 6.2 for most hydroponic systems) is crucial to ensuring that plants have access to all the nutrients they need.

How does lowering pH affect my plants?

When the pH in a hydroponic system drops, it can negatively impact your plants. At lower pH levels, necessary nutrients like calcium and magnesium become less available, leading to deficiencies.

Additionally, low pH increases the solubility of toxic elements such as aluminum and manganese, which can harm plants.

Symptoms include stunted growth, dim green leaves, and root damage. Regularly monitoring and adjusting pH levels can facilitate prevent these problems, providing a vigorous environment for plant growth.

Practical Apply Case: How Low pH Can Benefit and Harm Your Hydroponic Plants

In a study published in HortScience, researchers examined the effects of low pH on basil plants in hydroponic systems. They found that maintaining a nutrient solution pH of 4.0 effectively inhibited root rot caused by the pathogen Pythium aphanidermata.

However, low pH also disrupts nutrient uptake by increasing potassium and aluminum concentrations while decreasing phosphorus, calcium, magnesium, sulfur, boron, manganese and zinc levels in basil leaves.

This highlights the tender balance required to manage pH levels in hydroponic growing. While low pH can facilitate control some diseases, it can also lead to nutrient imbalances and potential toxicity. Regular monitoring and careful adjustment of pH levels are necessary to maintaining optimal plant health and growth.

Practical solutions to prevent pH changes

Maintaining a stable pH level in hydroponics doesn’t have to be complicated. However, pH imbalances need to be addressed urgently to optimize nutrient uptake and prevent plant damage. That said, elementary solutions present themselves in the following steps.

• Invest in a Dual pH System: Implement a pH controller, such as the one offered by Growee, which includes a sharp algorithm that controls both up and down pH adjustments, preventing drastic changes and protecting plant roots from pH fluctuations. This system constantly monitors pH levels and makes adjustments in real time, saving growers time and effort. Plus, you can track and adjust pH levels anywhere with the app.

• Apply pH Up/Down Solutions: These chemical additives balance pH levels, correcting any sudden rise or fall. Keep a solution on hand for quick exploit for minor adjustments.

• Choose a Reliable Nutrient Formula: Not all nutrient formulas are created equal. Unfortunately, they can affect pH fluctuations. Choose nutrient formulas designed for hydroponics and get into the habit of changing the reservoir every 1-2 weeks.

• Add Organic Buffers: If you want a more natural approach to maintaining pH balance in your hydroponic system, choose organic buffers such as fulvic acid, humic acid, amino acids, and kelp extract. These substances stabilize the pH of the nutrient solution, especially if acids and bases are added. They are derived from organic matter commonly found in decaying plant and animal parts.

• Stabilize Temperature: Maintain temperature between 20-25oC. Higher temperatures can escalate microbial activity, which can cause pH fluctuations.

• Prevent CO2 levels from rising: Too much carbon dioxide can lower pH levels. Make sure you have adequate ventilation in your hydroponic system and the room where your equipment is located to ensure adequate air circulation.

Which solution works best for you will depend on your hydroponic setup and preferred level of convenience. However, all operations require regular monitoring of your plants and environment to ensure nothing goes unnoticed—whether it’s pH, CO2, or temperature inconsistencies.

Application

pH drift is a common challenge in hydroponic systems, but with the right tools and knowledge, it can be effectively managed. For example, a pH controller offers an advanced solution, ensuring stable pH levels and promoting vigorous plant growth. By understanding the causes of pH drift and using reliable technology, growers can achieve better results in their hydroponic endeavors.

Frequently asked questions

What is pH drift in hydroponics?

pH drift refers to the gradual change in the pH level of a nutrient solution over time, which can affect plant health and nutrient absorption.

Why do pH fluctuate in hydroponics?

Several factors affect pH change, including nutrient depletion, water changes, and microbial activity in the nutrient solution.

How does reverse osmosis water affect pH change in hydroponic crops?

Using reverse osmosis (RO) water can cause pH fluctuations because it lacks the minerals that stabilize pH levels. As a result, it is more susceptible to changes when nutrients are added.

Does the type of hydroponic system affect pH change?

Yes, recirculating systems such as DWC, NFT, RDWC and Ebb and Flow are more susceptible to pH fluctuations due to the constant changes in the nutrient solution.

Can a float valve cause pH to rise?

Yes, a float valve can cause the pH to rise by adding plain water with a higher pH, diluting the nutrient solution and raising its pH over time.

How does increasing pH affect my plants?

Rising pH levels can reduce the availability of necessary nutrients such as iron and manganese, leading to deficiencies and plant deterioration.

How does lowering pH affect my plants?

Lower pH levels can reduce the availability of nutrients such as calcium and magnesium and escalate the solubility of harmful elements such as aluminum.

How can low pH be beneficial and harmful to hydroponic plants?

Low pH can facilitate control diseases such as root rot, but it can also cause nutrient imbalances and potential toxicity, requiring careful monitoring and regulation.