Water Quality Monitoring and pH Sensors in Hydroponic Gardening

Hydroponic gardening has become increasingly popular throughout the U.S. and abroad. This gardening system involves a unique production method where crops are grown in a nutrient-rich solution instead of soil. While these systems are somewhat new, they continue to improve with new variations and customization options that increase yield rates.

Even though hydroponic systems can be paired with outdoor crops, they are often placed in greenhouses. By installing a hydroponic system in a greenhouse, you’ll be able to control every aspect of the environment as well as the types of nutrients that your crops receive.

From leaf lettuce and herbs to tomatoes and peppers, there are numerous crops you can grow with a hydroponic system. To enhance plant health and yields, you must maintain high water quality. Plants often require specific nutrient and water quality levels to remain healthy. In this guide, you’ll learn how to monitor water quality in your hydroponic garden.

Woman with Hydroponic System

What Is Hydroponics?

Hydroponics is a gardening method that allows you to grow crops without soil. These systems use a combination of light, water, and nutrients to maintain growth. It’s possible for hydroponic systems to be as small as a laptop or as large as a lengthy shelf or table. Since hydroponic systems rely on nutrient-rich water, you can use them in nearly any environment. The main advantage of this type of system is that it doesn’t rely on soil or perfect outdoor conditions.

You’ll discover that there are numerous types of hydroponic systems that you can purchase for your home or greenhouse. The system you choose depends on the conditions in your space as well as the types of crops you wish to grow.

Among the most common types is the wick system. If you purchase this system for your crops, the roots of each plant will grow downward by absorbing nutrient-filled water. This water is sent to the crops via a large reservoir. The growing media that the crops are placed in makes it possible for oxygen to get to the roots and maintain optimal growth.

You can also obtain an air-gap system for your greenhouse or home. This system is designed to allow plant roots to be partially suspended in nutrient-rich water. The upper portion of each root is exposed to the surrounding air.

Consider the ebb and flow system as well. With this system, plant roots are placed directly into a medium. High-quality water will be pumped into the root zone every 30 minutes or so, after which it drains into a reservoir.

With a raft system, plants are placed on a floating surface, which allows the roots to be suspended in nutrient-rich water. A large pump unit supplies oxygen directly to the water. The oxygen dissolved before being absorbed by the roots.

You can also buy a top feeder system. This setup also requires placing the roots of your crops in a medium. The specific growing medium you use allows oxygen to get to the roots. On the other hand, the water will be sent to the top of your medium, which allows it to slowly filter down to the root zone before it drains to the nearby reservoir. This system mimics the standard rainfall percolation effect that occurs in soil.

Among the most common types of hydroponic gardening systems is one that uses the Nutrient Film Technique (NFT). When using this system, you’ll place your crops on a floating platform that hangs in a trough. The trough is slightly tilted to allow water to flow through and come into contact with the roots.

The upper portion of the root system is exposed to oxygen, while the bottom part is placed in nutrient-rich water. This water is sent into the trough along the upper end of the system. Once it flows past the root systems, it will be collected in a reservoir.

You may also consider using an aeroponics system. If you opt for this system, you’ll place the roots of your plants in an enclosed area. These roots are exposed to oxygen, while water flows into the enclosed space every 30 minutes. The water can also be sprayed onto the roots as a fine mist.

The Role of Water Quality in Hydroponics

To create an effective hydroponic system, you must focus on water quality, which takes time and patience. Make sure you test your water regularly to ensure you maintain specific nutrient concentrations. The water will also need to be changed often to refresh it and make sure your crops are growing properly.

Since this type of growing system requires you to place roots in nutrient-rich water, you’ll need to monitor it constantly. Any issue with the water quality must be addressed immediately. The most common problems with water quality in hydroponic systems include the following:

  • Roots aren’t receiving enough oxygen
  • Electrical conductivity is too low or too high
  • Water is old and stagnant
  • High concentration of contaminants
  • pH levels are too low or too high
  • Nutrient solution is too cold or too hot

The right water quality increases plant growth and makes it easier for roots to absorb nutrients. When water circulates through hydroponic systems, aeration is provided to the solution, which allows the roots to receive oxygen even if they aren’t exposed to the surrounding air. Every plant you place in a hydroponic system has a specific pH and EC range that you must maintain for ideal growth rates.

pH sensor for hydroponicspH sensor for hydroponics

Key Components of Water Quality Monitoring

As touched upon previously, hydroponic systems must be regularly monitored to maintain high growth rates. Successful hydroponic gardening requires consistent updates to the nutrient-rich solution you’re using. There are several water quality parameters you can track when you’re monitoring your system, which include temperature, dissolved oxygen, and nutrient concentration.

The roots of your plants can thrive when kept at a specific temperature range. Let’s say that your reservoir consists of a cold floor that’s made from concrete or a similar material. This material can shock the roots whenever you water your plants. It’s possible to mitigate this issue by placing a piece of plywood between the surface and the plant roots.

Root zones require specific temperatures to remain healthy and absorb a considerable amount of nutrients. Soil isn’t used as an insulator in hydroponic systems, which is why it’s crucial that you maintain the right temperature range. Your nutrient solution should be around 60-75 degrees Fahrenheit. You might be tasked with warming or cooling the water depending on the temperature in your grow room.

While there are several methods you can use to maintain temperatures in the nutrient solution and effectively grow your crops, consider warm lights. You’ll likely contend with the water getting too hot on occasion. However, this isn’t a significant problem.

If warm water becomes an issue, move the reservoir further away from your plants. You can also add insulation to the reservoir. When your nutrient solution becomes too cold, use a heater to increase the temperature. If you’re using warm lights, consider placing the reservoir closer to your plants.

The nutrient concentration is also an essential component of every hydroponic system. This solution provides your plants with all the nutrients they need, which is why they can grow even when they aren’t in soil. The three main nutrients that are used in these systems are potassium, nitrogen, and phosphorous.

Nitrogen is directly responsible for leaf growth. It also helps with the production of enzymes and proteins. Potassium boosts plant health and increases disease resistance, which should lead to better yields. As for phosphorous, it assists with flower formation and root development. These nutrients work in tandem to keep plants healthy throughout the growing process.

Hydroponic systems also benefit from using several different secondary nutrients to improve plant growth. These nutrients include sulfur, calcium, and magnesium. Sulfur assists with enzyme activity and protein synthesis, while magnesium boosts the production of chlorophyll. Calcium is important for providing stability to plants while also strengthening their cell wall structures.

While maintaining specific nutrient concentrations in your water, you’ll also be tasked with minimizing the contaminants that are introduced by outside sources. For example, dust that floats into the grow room can get into the water and impact its quality. If you use tap water in your solution, you’ll need to contend with different types of chemicals and additives that can negatively affect the plant’s balance.

Dissolved oxygen is also an important aspect of most hydroponic systems. For example, let’s say that you purchase an NFT system for your greenhouse. In this system, the lowest portion of the root system will sit in a shallow nutrient solution. However, these roots can’t survive unless there’s a considerable amount of dissolved oxygen (DO) in the nutrient solution that passes through the roots. If DO levels are lower than intended, the plant’s feeder roots could suffocate and die off.

Keep in mind that dissolved oxygen ties in directly with the temperature of your nutrient solution. Warm water holds considerably less oxygen than cooler solutions. Once the water reaches higher than 80 degrees Fahrenheit, it becomes much more difficult for the solution to hold dissolved oxygen.

Make sure you design the pump room to maximize the amount of re-oxygenation that occurs. The methods you can use to increase dissolved oxygen concentration in a pump room include the following:

  • Install an oxygen injector directly on the pump bypass. It should be placed around 200mm below the current water level. The injector will oxygenate the water and push waste gases to the surface.
  • Make sure the nutrient solution you’re using cascades through clean air and onto the top of your tank.
  • Consider using air compressors or air blowers to oxygenate the lowermost portion of the tank.
  • You can install sprinklers along the pump bypass to spray jets of water onto the tank water surface.
  • Place white pipework or white floor coverings in your hydroponic system to reflect heat away from the water. This technique allows you to more effectively maintain water temperatures in your hydroponic system, which should help with DO levels.

pH Sensors in Hydroponics

While it’s crucial that you maintain the right electrical conductivity and nutrient levels, you must also focus on pH. The pH of a solution refers to its acidity or alkalinity. Water pH can range from 0-14. When the scale drops below 7.0, the water is acidic. It also becomes progressively more acidic as you go further down the scale.

If the water’s pH level is higher than 7.0, it’s alkaline. If a high concentration of dirt and other contaminants is in the water, it will likely be acidic and taste bad. It could also cause health problems. However, high pH levels can be problematic when it comes to the health of your crops.

Plants are able to absorb nutrients through their roots. However, a plant’s absorption rate depends on the water’s pH. When the water is acidic, the roots will absorb manganese, aluminum, and hydrogen. If the solution is highly acidic, absorption rates will be too high, which can be toxic to your plants.

Acidic pH levels also lead to less absorption of magnesium and calcium, both of which are important for maintaining the health of your plants. In alkaline environments, your plants will receive more macronutrients and molybdenum. On the other hand, they won’t get as much iron, copper, cobalt, and zinc. By maintaining the ideal pH level for your plants, you’ll be able to keep your hydroponic plants healthy. You can monitor the pH of your water with a pH sensor or meter.

Benefits of Water Quality Monitoring and pH Control

There are many advantages associated with monitoring the quality of your water and controlling its pH. For example, this strategy improves the health of your plants while also increasing growth rates. This technique should boost your yields as well as the quality of your produce. The crops you grow will inherently be more valuable.

By effectively reducing waste and using nutrients more efficiently, you’ll save a considerable sum of money. The ideal pH range for hydroponic systems depends on the type of crop you’re trying to grow. In general, you should aim for a pH of 5.5 to 6.5. However, mint plants require a pH range of 7.0 to 8.0. If the pH of your solution is too high or too low, the water may need to be filtered to remove the following contaminants:

These contaminants might inhibit plant growth. If you need to improve the quality of your water and reduce contaminants, consider reverse osmosis systems or rainwater. Reserve osmosis is a powerful water filtration technology that removes molecules, large particles, and ions from water.

If you use a nutrient mixture, you can purify the water before adding the mixture and using it in your hydroponic garden. Rainwater is a more environmentally friendly solution that’s low in minerals and contaminants. The only drawback is that it can be difficult to collect rainwater.

Common Misconceptions About Water Quality and pH in Hydroponics

There are numerous misunderstandings and misconceptions about the complexity and cost of monitoring systems and hydroponic gardening setups. While hydroponic gardens come with high upfront costs, you should save money by creating high-quality produce and generating better yields.

When you’re searching for the best pH sensor to install in your garden, keep in mind that there are many options to choose from. They cost anywhere from $100 to more than $1,000. The sensor you select for your hydroponic system depends on the size of the garden. If you have a larger hydroponic system that requires continuous monitoring, you’ll likely benefit from using an intelligent pH sensor that delivers precise readings.

There’s also a slight learning curve associated with water quality management and hydroponics. On the other hand, you don’t need extensive knowledge of water quality parameters to take readings and determine what your next course of action should be. With the right system in place, you don’t need to spend much time monitoring the quality of the water in your hydroponic system. When using a reliable pH sensor, you should receive a reading within 30 seconds to a minute.

hydroponics pulling planthydroponics pulling plant

Practical Tips for Monitoring Water Quality and pH

Once you decide to start monitoring water quality in your hydroponic system, you need to obtain the right tools and sensors. As touched upon previously, there are many unique pH sensors at your disposal. You can also obtain an electrical conductivity sensor to more effectively measure the concentration of contaminants in the nutrient-rich solution.

When you’re searching for the right pH sensor, consider a modular in-line one. In-line probes are designed to be paired with heavy-duty applications. While these probes wear out faster than other pH sensors, the modular design allows you to replace the sensor in a matter of seconds. This tool offers reliable performance no matter the application. You’ll also benefit from low maintenance costs.

If you want to purchase a conductivity sensor, you have access to toroidal and contacting units. Toroidal conductivity sensors are designed to effectively eliminate the polarizing effects that are known to occur in contacting sensors. Contacting sensors are more affordable but may not provide consistent results.

To maintain optimal water quality in your hydroponic system, it’s highly recommended that you take measurements at least once every day. If you find that the quality of the water has fallen outside of the ideal range, you may need to filter the solution. Use your pH sensor or conductivity meter to determine what your next steps should be. You may need to filter the water to eliminate the contaminants that have altered the pH level.

Integrating Water Quality Monitoring Into Your Hydroponic Setup

If you want to integrate water quality monitoring into your hydroponic setup, it’s a good idea to purchase in-line sensors that can be submerged directly into the solution. By obtaining continuous measurements, you’ll know when the water needs to be refreshed or treated. Performing regular checks allows you to make instant adjustments for optimal results. If your crops are always kept in perfect conditions, you’ll benefit from high yields and fantastic growth rates.

Conclusion

Hydroponic systems require high water quality and comprehensive pH management. The crops you grow must be kept in specific pH ranges to ensure the best growth rates. To gain better hydroponic gardening success, invest in reliable monitoring tools that will deliver accurate readings.

Source link: https://sensorex.com/hydroponic-gardening/ by Joshua Samp at sensorex.com