resevior water temp

mishin31

Active Member
what should my resevoir water temp be. I'm assuming it is to hot right now (80 degrees) but just wondered what it should be at
 

researchkitty

Well-Known Member
Oh, and by the way, for a very energy efficient means of cooling your res down, open the lid and just blow a little $5 walmart fan over the top of the res water. That'll knock it down 6-7(f) for 0.1amps. :)
 

fatman7574

New Member
Depends on your growing system type and the quality of its design/construction and other factors. Water temperature temps like water nutrient reservoir DO levels are one of those areas where a lot of people hold on to old myths vigorously rather than admitting that it is mainly a function of the ability to run your system in a fashion where all water with n the system has DO at all times. If your systems has water laying around in contact with roots at any time or place then you will have problems regardless of the reservoir temps or the reservoir DO level. PERIOD.

Some people try to say all this can be addressed by maintaining low reservoir temps as lower temp water holds more DO. That is simply an unfounded myth that some refuse to let go of. Consider this: plants actually need very little DO. Less that 2 ppm in all likelihood is just fine as long as all the roots receive that amount. That means the inside and the outside of the root mass. However most systems are designed, built and operated so poorly that the water is often stripped of all DO and the water sits in depressions and lays in tubes, trays, buckets and trough bottoms with roots laying in it.

Rather than improving systems people created the Myth as k lower nutrient water low temps allows higher DO that will solve the the problem without ever actually addressing the actual problem(s). Low DO is merely a result or symptom of the problem, not the problem itself.

At 64.4 degrees F (18 Celsius) the water will hold 9.45 ppm of dissolved oxygen (DO). At 70 degrees F (21 degrees C) it will hold 8.9 ppm or At 86 degrees F the water will still hold 7.54 ppm of DO. That is 80% of the 64.4 Degree amount. Considering that the plants only need about 25% percent of that 64.4 degree amount of DO and likely even less than that it shows the temp/DO myths are simply hard for some people to let go of. There is no basis for the myths.

There is the fact that oxygen loving bacteria need oxygen. However in an inert hydro system with chemical fertilizers there are never enough bacteria/pathogens or enzymes to need anything but a negligible amount of bacteria unless there are system design/construction and operation problems. If you have such problems lower temps or higher reservoir DO is not going to stop the problems, as your talking only 25% more DO.

If your system is already eating up 3 times more DO then it should need then another 25% will make little difference in preventing a very low or zero DO water accumulation somewhere that will allow for root rot to start. This will mean a production of food for oxygen loving bacteria which will cause a higher demand on DO but with ho high Reservoir DO the bacteria will have everything the need to multiply even more, food and DO. Oh my.

Build better systems operate them as well as you can and don't perpetuate low temp high DO reservoir myths. If you want to see how well a low temperature high DO reservoir supports bacterial growth just visit your local waste water treatment plant. They pump massive amounts of air into the aeration basins so as to support massive bacterial multiplication to break down organics. Treatment plants operate outdoor all winter long almost everywhere in the U.S. the U.S.'s only indoor sewage treatment plants are in Alaska.

While it is true that CO2 is a factor that limits many growers to lower temps, it is poor design and operating problems that cause the problems blamed on low DO and high reservoir temps not the nutrient temp itself.
 
Top