Nutrient Temperature - Oxygen and Pythium in Hydroponics
by Dr. Lynette Morgan, Courtesy of NA Greenhouse
http://www.simplyhydro.com/nutrient_temp.htm
The hydroponic nutrient solution is not just a mix of fertilizer salts and water… 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.
… 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 aerated solution at 10°C (50° F) is about 13ppm, but as the solution warms up to 20° C (68° F) the ability of the liquid to 'hold' oxygen drops to 9 - 10ppm, by the time the solution has reached 30° C (86° F), then it's only 7ppm.
QUESTION # 1: What is the real cause of Pythium fungal infestations (Root Rot disease) in hydroponics?
1. high nutrient water temperature > 68 F
2. low dissolved oxygen in the nutrient solution and root zone? 1-6 ppm
100% DO saturation at 68F–sea level barometric pressure- solute concentration 0 is 9.2 PPM WITH AIR (AERATION) 20% OXYGEN
Have any opinions and/or actual experiences with Pythium fungi infestations or other serious root diseases?
Cheers
J
by Dr. Lynette Morgan, Courtesy of NA Greenhouse
http://www.simplyhydro.com/nutrient_temp.htm
The hydroponic nutrient solution is not just a mix of fertilizer salts and water… 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.
… 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 aerated solution at 10°C (50° F) is about 13ppm, but as the solution warms up to 20° C (68° F) the ability of the liquid to 'hold' oxygen drops to 9 - 10ppm, by the time the solution has reached 30° C (86° F), then it's only 7ppm.
QUESTION # 1: What is the real cause of Pythium fungal infestations (Root Rot disease) in hydroponics?
1. high nutrient water temperature > 68 F
2. low dissolved oxygen in the nutrient solution and root zone? 1-6 ppm
100% DO saturation at 68F–sea level barometric pressure- solute concentration 0 is 9.2 PPM WITH AIR (AERATION) 20% OXYGEN
Have any opinions and/or actual experiences with Pythium fungi infestations or other serious root diseases?
Cheers
J