This is a thread for people who have root rot issues. Many people cannot simply use clean water and expect the 99% success rate that others experience. I will be playing with both beneficial microbes and sterilization agents. In saying that, I should also note that I have no desire to run a sterile reservoir beyond the clone phase. Successful innoculation of beneficial bacterial, and/or a fungal species like Trichoderma can protect the culture from pathogens while also forming a symbiotic relationship, increasing nutrient uptake by plants and decomposing dead organic matter. One product I'm interested in is called Banrot (etridiazole & thiophanate methyl). It's a wide spectrum fungicide that covers Pythium, Phytophthora and Fusarium among others. Anecdotal evidence I've found on the net indicate 25-50ppm is effective in hydroponics for sterilization purposes, though much higher rates have been used. Here's a link to a thread with several people taking about their experience with it. https://forum.grasscity.com/threads/pythium-saga-in-rdwc.1317376/ Another chemical fungicide I have is called Daconil Fungicide (Chlorothalonil). While it's something that can be found in hardware stores, it doesn't specifically list Pythium and is typically used as a foliar application. I'll be trialing it because it's easier to get and can be purchased in smaller amounts. Smallest bag of Banrot seems to be 2lb. of powder which is in the $80-90 range while Daconil Fungicide concentrate can be purchased for around $20. Other sterilizing agents I will use are sodium hypochlorite (bleach) (2-4ppm), and peroxide. I'm still unclear on the upper levels of peroxide as I have read accounts indicating ppms approaching 100 not being harmful to mature plants. I've already discovered that clones will root at 10ppm in a bucket cloner, water being changed every three days. I will probably try a spread of around 5-50ppm and see what the results are. Note on hypochlorite: this form of chlorine reacts with nitrogen to form chloramine. If used in a nutrient solution there will be no chlorine present and the amounts necessary to provide a benefit will change since chloramine isn't as toxic as chlorine. I will be culturing in plain water so not an issue for cloning, but I may introduce low ppm bloom nutrients several days prior to transplant. At that point I will likely rinse the media free of chlorine and inoculate with a beneficial of some kind (which one tbd) so still not an issue. And while this thread isn't about curing root rot in vegetative or flowering plants it's worth noting that large quantities of bleach in nutrient solution have proven unable to cure root rot. The chlorine is converted to chloramine within minutes and while high levels of chloramine may be effective in sterilizing the water, pathogens that have burrowed into roots can withstand those same sterilization levels. There is some preliminary evidence suggesting that soaking roots in plain water with 4ppm hypochlorite is effective at destroying established root rot, but that's a topic for another thread. I have two microbial products. One is a pure Trichoderma powder called Root Shield. Trichoderma will attack other bacteria and fungi and can be very aggressive in the right conditions. Trichoderma is noted to burrow into the cellular structure and feed off plant sugars while increasing elemental nutrient uptake to the plant. The other is a bacterial product called Hydroguard which contains Balillus Amyloliquefaciens. This species can also be found in higher concentration (better value) in a product from Southern AG called Garden Friendly Fungicide. So, those are the chemicals I have to play with. In addition to the active ingredients I'd also like to do some testing with tap water, boiled tap water, and purified drinking water (bottled). I'll update as I have results and observations. Other contributions are welcome. If you've had root rot issues and conquered them please share. Would be interesting to read about other chemicals, useful ppm concentrations for bleach and peroxide, worm casting tea in the clone stage, etc.