What about nutrient solution temperature?
The hydroponic nutrient solution is not just a mix of fertilizer salts and water, there are a number of organisms and compounds commonly found in our hydroponic systems that we need to be aware of. One of the most important of these is dissolved oxygen, which is vital for the health and strength of the root system as well as being necessary for nutrient uptake. Most growers are familiar with the need to have some form of aeration in their nutrient solution – whether they be in a recirculation or a media based system. In NFT systems, this is often accomplished with the use of an air pump or by allowing the nutrient to fall back into the reservoir, thus introducing oxygen. However, the effect of temperature of the solution on the dissolved oxygen levels and on root respiration rates also needs to be taken into account. As the temperature of your nutrient solution increases, the ability of that solution to ‘hold’ dissolved oxygen decreases. For example, the oxygen content of a fully a