Really love a set of scales to keep track of weight too. pH and EC are both critical for thriving plant health, but temperature also plays a pivotal role in achieving optimal growth. It also happens to be the fundamental parameter that's most commonly overlooked. When you think about temperature in the context of a growing environment, you could be referring to the temperature of the air around the plants or you could also be referring to the temperature of nutrient solution or irrigation water, which will affect the root zone temperature. While air temperature is important, for the purposes of this piece, I'll be focusing on root zone temperature and its effect on nutrient uptake and overall plant health. That's because a plant's root system is the location of two essential chemical processes: water and nutrient absorption. In each of these processes, having the correct root zone temperature is paramount for these to occur efficiently. In a nutshell, root zone temperature will affect the rate at which your plants are able to absorb nutrients. If you let your root zone temperature remain unmonitored and uncontrolled, this could lead to disastrous effects on your overall crop yield. Nutrient absorption is largely driven by chemical processes, which take place in your plants' roots; the efficacy of these processes is determined by the temperatures to which those roots are exposed. Once your root zone temperature moves out of its optimal range, the plant will not be able to deliver optimal levels of nutrients and water. Ideally, you should aim to have your nutrient solution or irrigation water temperature at around 18 – 22 °C (65 - 72 °F) to ensure optimal nutrient and water uptake. In addition to having an effect on nutrient absorption, your root zone temperature also affects oxygen availability and solubility. If your water is too warm, you could risk starving your roots of oxygen as warm water cannot hold as much dissolved oxygen as colder water. On the other hand, if your water is too cold, this could shock your plant roots, decrease plant metabolic rates, and stunt plant growth.