Irrigation in hydroponic systems: The right balance between water and nutrients

Hydroponic systems offer many benefits for indoor growing, most notably precise control over nutrient delivery and plant growth. However, to get the most out of your hydroponic system, finding the right balance between water and nutrients is crucial. In this guide, we'll show you how to determine the ideal amount of water and nutrient concentration for your plants to encourage healthy roots and bountiful yields.

1. Why the right amount of water is important

In hydroponic systems, plants grow without soil, but instead their roots are directly submerged in water or sprayed with a nutrient mixture. The amount of water plays a crucial role, as it not only hydrates the plant but also serves as a medium for nutrient delivery. Too much or too little water can significantly affect plant growth.

Benefits of the right amount of water:

• Optimal root growth: A constant water supply ensures healthy and strong roots.
• Improved nutrient uptake: The right amount of water helps plants absorb nutrients efficiently.
• Preventing root rot: A balanced water supply prevents the roots from standing in water for too long and rotting.

2. Water cycles in different hydroponic systems

Depending on the type of hydroponic system, water cycles and methods vary. Here are some of the most common hydroponic systems and how they affect water management:

deep water culture (DWC)

In deep water culture, the plant roots are constantly suspended in a water-nutrient mixture that is continuously enriched with oxygen. With this system, it is important to keep the water level constant and to ensure sufficient aeration.

• Water level: Keep the water level just below the plant roots so that they can absorb oxygen and nutrients at the same time.
• Aeration: Use an air pump to oxygenate the water and aerate the roots.

ebb and flow system

With the flood and drain system, the root area is regularly flooded with a nutrient mixture and then drained again. This gives the plants phases in which they receive both water and oxygen.

• Watering cycles: Flood the root area 2-4 times daily, depending on the growth phase and substrate.
• Ensure drainage: Make sure that the water drains away completely to avoid root rot.

nutrient film technology (NFT)

In the nutrient film technique, a thin film of water enriched with nutrients flows continuously over the roots of the plants. This system requires precise control of the water flow to ensure that the plants receive sufficient nutrients.

• Continuous flow: Make sure the water film flows evenly and the roots are always in contact with the nutrient water.
• Flow rate: The speed of water flow should be adjusted to ensure that the roots receive enough oxygen.

3. The right nutrient concentration

Nutrients in hydroponic systems are supplied via water, so it is crucial that you closely control the concentration of nutrients in the water. Too high a nutrient concentration can burn plant roots, while too low a concentration can slow growth.

Tips for nutrient concentration:

• Monitor EC: Use an EC (electrical conductivity) meter to monitor nutrient concentration. The ideal EC is between 1.0 and 2.5 mS/cm, depending on the plant species.
• Renew nutrient solution regularly: Change the nutrient solution in the system every 1-2 weeks to ensure that the plants always receive fresh nutrients and that no waste products accumulate.
• Phase-dependent nutrients: Adjust the nutrient concentration depending on the growth phase. In the vegetative phase, plants need more nitrogen, while in the flowering phase they need more phosphorus and potassium.

4. Check the pH value in the hydroponic system

Another important factor in achieving the right balance between water and nutrients is the pH of the nutrient water. If the pH is not in the optimal range, the plants will not be able to absorb the nutrients efficiently, even if they are present in sufficient quantities.

Tips for pH control:

• Measure pH regularly: Check the pH of your nutrient water at least once a day. The ideal pH for hydroponics is between 5.5 and 6.5.
• Adjust pH: Use pH Up and pH Down solutions to correct pH as needed. Make sure to make adjustments gradually to avoid fluctuations.

5. Oxygen supply to the roots

Oxygen is just as important as water and nutrients. Since the roots in hydroponic systems are constantly in contact with water, it is crucial that they receive sufficient oxygen to stay healthy and minimize the risk of root rot.

Tips for oxygen supply:

• Air pumps and air stones: Use an air pump in combination with air stones to continuously oxygenate the water in your system.
• Avoid overwatering: Make sure the roots are not completely submerged all the time, especially with systems like DWC or Ebb and Flow. They should always have access to oxygen.

6. Common problems with irrigation in hydroponics

Even a well-organized hydroponic system can experience problems if the water and nutrient balance is not right. Here are some common problems and how to fix them:

root rot:

Root rot occurs when the roots are left in water for too long and do not receive oxygen.

• Solution: Improve aeration and ensure roots get enough oxygen. Reduce watering time on systems like ebb and flow.

salt deposits:

Salt deposits are caused by excessive nutrient concentrations and can damage the roots.

• Solution: Flush the system regularly with clean water to remove excess salts and monitor the EC value.

Conclusion

Irrigation in hydroponic systems requires a careful balance of water, nutrients and oxygen. By regularly monitoring and adjusting water levels, nutrient concentrations and pH levels, you can maximize your plants' growth and promote healthy roots. With proper care, your hydroponic system will become an effective tool for high yields and strong plant growth.