Hydroponics is a practice where plants are grown in a specially designed medium rather than regular soil. A key feature of this method of growing plants is the use of water regulated closely within pre-determined temperature levels.

Additionally, nutrients required to ensure that hydroponically grown plants thrive are supplied through a nutrient solution. Essential nutrients delivered to the growing plants include nitrogen, potassium, phosphorus, calcium, sulfur, magnesium, manganese, boron, copper, zinc, and iron.

How Does Water Temperature Affect Plant Growth?

Although there is a well-established relationship between water temperature and plant growth, the science of temperature regulation to achieve the best possible conditions for plant growth is not exact. The temperatures necessary for optimal development vary between plant species.

For example, while some plants such as onions and cucumbers tend to thrive at higher temperatures, others like lettuce require lower temperatures.

Is There an Ideal Hydroponic Water Temp?

Nutrient solution temperature influences several important variables, foremost of which are oxygen solubility and plant metabolic processes. With rising temperatures, the rate of metabolic reactions occurring in the plants will increase. Conversely, levels of available oxygen will start to decline as respiration rates due to the elevated plant metabolism will use up available stores faster than they are replenished.

Consequently, determining the ideal water temperature for hydroponics is dependent on reaching a compromise between plant oxygen usage and metabolism. In most cases, however, commercially cultivated plants will thrive in temperatures ranging from 59-86°F.

How to Keep DWC Water Cool

Deepwater Culture (DWC) is a hydroponic method of cultivation where plant roots are suspended in an oxygenated, nutrient-rich solution. For planters to utilize this growth technique, maintaining an ideal hydroponic reservoir temperature is vital to achieving optimal results.

In the course of their operations, deep water culture systems tend to experience temperature increases which, if left unchecked, could adversely affect the health of the plants they supply. Outlined below are some of the best ways to cool a DWC system.

Invest in a Water Chiller

This is the single most effective way to handle undesirable spikes in temperature of DWC water. For growers who have multiple DWC systems to manage, acquiring a hydroponic water chiller is the smartest choice to make.

Once installed, a single chiller can handle a wide volume of water (with or without nutrients). The larger the volume, the larger the chiller capacity required. The temperature controls on the chiller will automatically detect and modify cooling temperature as necessary, creating an environment for hydroponically grown plants to thrive.

Wrap/Paint the Reservoir

Another way to achieve some level of DWC water temp control is to either paint the exposed surfaces of the reservoir white or wrap it in reflective material. This will deflect sunlight or artificial light, preventing it from striking the plant surfaces and generating heat.

Insulate the DWC System

Wrapping the reservoir in insulating material will help to keep out the heat and maintain a cool environment inside the deep water culture. Insulation jackets can be customized to serve this purpose.

Use Cooling Fans

Cooling fans can be used to directly cool heat emanating from a reservoir. Some available aquarium fans can be satisfactorily utilized with hydroponic reservoirs as well. The drawback to using fans for cooling is they can significantly increase the humidity of the system.

Situate Indoor Reservoirs Away from Heat Sources

The ideal location of an indoor hydroponic reservoir is as far away from sources of ambient heat (hot lights, heated equipment) as possible. Locating the reservoir in a cool place helps minimize the transfer of heat from these sources, keeping your hydroponic water temp at acceptable levels. 

Use Immersion Coils with a Temperature Controller

A temperature controller can be used to set a specific temperature and monitor the actual temperature of the reservoir. A temperature sensing probe is in the reservoir, and an electric solenoid valve is installed at the entrance of the stainless steel immersion coil.

During chilling demand, the chilled fluid from the chiller will flow through the immersion coil. When the temperature set point is reached the valve will close preventing the chilled fluid from flowing through the coil. This is an efficient use of the chiller’s cooling capacity; only providing heat removal to the tanks that are calling for cooling.

Bury Outdoor Reservoir Units

For hydroponic gardens located outdoors, placing the reservoir system beneath the ground can be a good idea. This will not only shield the reservoir from the heating effect of direct sunlight but also provide it with the natural cooling effect of ground soil.

Handle Root Rot

A vital aspect of achieving ideal water temp for hydroponics is properly handling the issue of root rot. This condition if left unchecked can significantly contribute to warming up the nutrient water in a hydroponic system.

Root disease thrives in warm water, so the warmer it gets, the worse the rot. There are several measures which can be taken to address rot disease including:

  • Identification and immediate removal of dead leaves and roots
  • Using mineral-based nutrients to prevent root problems
  • Application of enzymatic root area cleaners to minimize disease-causing sludge

Check Out Cold Shot’s Line of Hydroponic Chillers

Cold Shot Chillers manufactures some of the highest-grade hydroponic chillers suited for reliable cooling in your hydroponic gardens. Our agricultural chillers have capacities from 1.5 to 100 tons and are designed with the finest quality materials at our facility in Houston, Texas. We also provide a range of industrial water chillers for medical, metalwork, and brewery applications.

For consultations about your process cooling needs, please contact us online today or call us at 1-800-914-7370.