Yes, it has been very perplexing for me. I even spoke with ABF a couple of years ago about this problem and he could not think of anything. I am very open to the possibility that I am doing something wrong, but can't figure out what that could be. The water in my res gets changed out every other week and I drain all the water and clean all the equipment once a month.
Reading your earlier posts you said 1 watt per gallon to get enough air in the res when using BB. Is this only for DWC or also ebb and flow? I have a EcoPlus commercial 1 that is 18 watts and 38 liter/min. I have a 40g, 20g, and a 10g res. My air pump runs 12 hours during the time the lights are on and the tables are being flooded. When I start using the tea I am assuming I will have to run the pump 24/7?
Also do you think it would be worthwhile to add tea to the water I give to my cuttings? Maybe the BB could colonize the root mass and keep it protected for when it gets transplanted? I keep them in small RW cubes and use a heat mat to keep the RW at 84 degrees fahrenheit. Would cold water have a negative impact on the roots coming out of the bottom of the cube, or the cutting in any way?
Thank you for all of your help. It has been a pleasure reading this thread.