A crucial, yet often overlooked factor in hydroponic environmental control is the temperature of the nutrient solution.
The temperature of the nutrient solution impacts the amount of oxygen that can be transported to the roots. Cooler water is able to retain more oxygen, while warmer water retains less oxygen.
The optimum water temperature range is 18-22°c. The ideal temperature is 20°c.
At 25°c water can hold 5ppm of oxygen. At 20°c water can hold 8ppm of oxygen.
When the nutrient solution is too warm, plants may begin to suffer from heat stress. Symptoms of heat stress include wilting and root diseases. Warmer water temperatures also provide the optimum environment for pathogens (damaging microorganisms, fungi, and bacteria) to multiply in the nutrient solution, on the plants roots and in the root zone. The beneficial microorganisms that keep pathogens in check can't survive in the warmer water, allowing pathogens to multiply. Rotting roots caused by high water temps also feed the pathogens.
Cold nutrient solution problems don't occur as often, especially in Australia's relatively warm climate. However if the nutrient solution is too cold, it can stunt and slow plant growth.
We recommend the use of a water chiller during the warmer months. An effective water chiller can quickly chill 2 x 200L barrels of nutrient solution. A water chiller can also be used to regulate the temperature of multiple Turboklone stations.