The water temperature in hydroponic systems is something that many new gardeners tend to overlook. Most plants are better off with cool water, specifically water that’s between 65 and 70 degrees Fahrenheit. The pumps and lights of indoor hydroponic systems create heat, and in order to maintain a low water temperature, many gardeners use a chiller. It is very important to understand that cold water holds more dissolved oxygen than warm water. For example, water at a temperature of 65 degrees Fahrenheit has an oxygen capacity twice that of water at 85 degrees Fahrenheit. The water temperature is the conduit for oxygen to be absorbed by the roots.
Clear Rez can be used to kill bacteria when water temperature can’t be controlled.
The most common practice to add dissolved oxygen to water in hydroponic systems is the use of Air Stones and Micro-Pore Air Diffusers. Hydrofarm has a “venture aeration kit” with their Active Aqua 550 submersible water pump. They have a hose attachment that sucks air into the water and uses the water pump as an air delivery system. OxyClone 20 site cloning machines use what they call an “oxy head” which acts the same way.
Since your water needs to stay cool in order to hold dissolved oxygen, you do not want to be pumping warm air into the root zone from your air pump. Your air pumps should be kept in the coolest place you can find. The air you are pumping into your nutrient solutions should be colder than the room temperature, ideally 68 degrees. Remember, heat in the root zone will starve your plants of dissolved oxygen. Keep your pumps cool!!
High Water Temperature in Hydroponic Systems
Water temperature in hydroponic systems over 72 degrees can be a breeding ground for anaerobic bacteria. Because like earlier stated this higher temperature water cannot hold on to oxygen. Anaerobic bacteria thrive in this warm moist environment . There are products such as Clear Rez which will enable your reservoir to get warmer while killing off all bacteria. Clear rez is made with hypochlorous acid which is commonly found in pool shock.