How about you don't shift the burden of proof and shows us research that backs up your claims? Has it occurred to you that 80f is hot even for soil? You, not the chiller sellers, make a bold claim so the burden of proof is yours. Show us that 80f dwc run...
100% of what?
That condition you "provided" does not exist in reality, as you just learned. It's the max DO level that lowers when temp gets higher.
Sativied - I read some of your Picture Journal, I’m looking forward to reading it all. You’ve provided detailed technical information, references and technique along with great pic of your work. Clearly you are no novice in the trade.
Intellectual Honesty is duly noted, has validity, acknowledged and appreciated… Bravo
Have any of you ever actually tested the DO Sat in nutrient water with a DO Meter or just looked a DO charts and assumed all is well because the nutrient water is cool? DO Meters ar costly and you would need a real good reason to spent the money to buy one, Most people just guess and hope there’s plenty of air.
100% of what?...
DO saturation - Slow way down, go back and read the next 3 words after 100% in my sentence… “what?” is DO saturation. You just got besides yourself and skipped the rest of the sentence… now you know.
That condition you "provided" does not exist in reality, as you just learned. It's the max DO level that lowers when temp gets higher.
Well that’s what the DO Sat chart predicts with fresh water alright. Yes, this condition I spoke of is real and not something I just learned or made up. I learned this in 8th grade general science decades ago and The DO Sat chart has not changed a t all. Dissolved oxygen supersaturation really exist in reality. Check it out:
https://en.wikipedia.org/wiki/Supersaturation
Nothing to it, simply apply Henry’s Law
https://en.wikipedia.org/wiki/Henry%27s_law and you can easily understand how easy it is to achieve 150% DO supersaturation if you like in 80F nutrient solution. Keep the solute concentration stable, the nutrient temp at 80F and manipulate the fractional concentration of oxygen and or barometric pressure, maybe an additional ½ psi is all it takes (15.1 psi).
By the way, oxygen is not air. Air contains 79% Nitrogen and many other gases including a little bit of 21% oxygen. Air is extremely limiting when it comes to insuring safe oxygenation. Oxygen is, well, 99.9% oxygen.
But, it doesn’t seem that any of you have ever experiences a low oxygen issue in your experience so this thread may be meaningless unless you have had low oxygen problems negatively affecting you crop.
For anyone on this thread that has had low oxygen problems, try out this DO Calculator and apply Henry’s Law with different pressures, (1 ATM is 760 mm/hg or 14.7 psi), different DO saturations and different DO Concentrations and behold, you can really manipulate DO Sats and DO Concentrations when or if you ever have low DO problems. All kinds of new ways to saturate or supersaturate nutrient water. Henry’s Law could open doors of perception for you and introduce a lot of new possibilities for consideration.
http://water.usgs.gov/software/DOTABLES/
Thanks for joining in.
Now, let’s get back to my question please… Do you think the plants may be healthier, grow faster and be more productive if the grower could maintain his nutrient solution and root zone temperature at a constant 80F and maintainer the circulating air at 65-70F with good lighting of course? That is - provided the nutrient solution oxygenation is maintained at continuous 100% DO saturation throughout the whole system?
A simple yes, no or maybe will be fine.
Your thoughts?
J
