whitey - Ideally, I like space for 9-10 mature RDWC plants, 60 gallons water/nutrient recirculating, room temp and water constant 80F – 86F (keep plant and microbial metabolism on the high side), DO Sat 100% continuously, water pump 30 minutes on/off per hour, 12 V DC battery and DC water pump… the solution contains approximately ½ gallon (4.0 lbs.) of healthy, thriving micro-organisms?
I know that a 40 YO study says the celery plants do fine with 2 PPM DO which is often superimpose on RDWC pot plants somehow. I don't really buy that assumption at all.
I find that high oxygen is most import for collective plant and microbial aerobic respiration and preventing fungal infestation (I am pro fungal prevention vs. crisis intervention with fungal treatments post infection), 18F air and water temp insures and maintain higher metabolism for plants and good microorganism than 68F air and water temperatures, always satisfying oxygen demand with continuous oxygen supply and availability are critical factors that greatly influence plant and microbial health and mortality. Don’t forget that air is mostly nitrogen, not oxygen.
DO air charts are common, but I never try to insure minimal safe oxygenation with these charts and chillers… I insure oxygenation with an oxygen generator and test effluent DO Saturation often, always maintain 100% DO saturation (optimal oxygenation) 24/7 throughout the growing and budding period. No air pumps and bubble rocks, no mechanical aeration, no fountains and no water chilling. Maintain room air temp continuously @ 80 F with good ventilation flow and cyclic lighting…. And absolutely NO H2O2 that always kills the good microorganisms that I bought.
Plants and microbes do not need nor use nitrogen in respiration. When oxygen supply is short the fungi present and then thrive, fungi are opportunist and attack dead and dying plant material and microbes sick from insufficient low oxygen environments. Fungi are ubiquitous, they are opportunist like vultures that clean up/eat the dead. They will eat you too someday when you’re dead, cold, in the box, underground in the dark. The have an important place in the natures’ life cycles. They dispose of the mess after death.
No fountain pump. I’m not really concerned with the volume of air pumps deliver, but I am most concerned about insuring and maintaining the dissolved oxygen saturation continuously within a safe range for the combined plant and microbial eco-systems. Air and oxygen are different gases.
Want to learn something shocking? Contact any microbiologist (not the salesman) that works for any company that produces and sells beneficial microbes for pot plants. Ask that staff microbiologist, “what is the optimal dissolved oxygen saturation needed to maintain 1 gallon (8 lbs.) of their top-of-the-line microbes in 80F water in a thriving RDWC grow continuously for 4 months? I think the answer will be 100% DO Saturation continuous.
Most people have total faith in a DO Chart, “The DO chart says da-da-da…” Most growers have never actually tested the DO Sat, have no DO Meter and have no idea what their DO sat really is in their grow. All their oxygenation hopes and expectation are based only on that little DO chart, air and water temperature. Many assuming that as long as the water temp is in the 60’s F the oxygenation will be safe using air.
But, what if the fungus presents proving their dissolved oxygen is way too low and crisis alarm goes off… yikes, big problems, high stress, might lose the whole crop now! There’s a fungal infection in the root ball, a serious setback that requires crisis intervention and chemical treatments. Prevention in no longer an option now and intervention is activated because of a full blown fungal outbreak. It’s simply way too late for prevention then.
Most growers never have fungal outbreaks, but some do have this problem and all growers worry for months about possibly having fungal outbreaks.
Real time DO is demonstrated with a DO Meter and serial testing throughout the growing period, but you must have a DO Meter or another accurate chemical testing device. A DO chart does not measure real time DO and never will… the DO meter tells the tale accurately.
Plants and microbes always grow best when their metabolism is high and continuous high metabolism always requires a lot of oxygen… a lot of air is not the same as lot of oxygen, contrary to popular belief.
You all have a Rocky Mountain High Christmas sitting by a warm fire with a big J burning and homemade eggnog.
