I use uv lights in my ro tanks just for pythium. There's no protection in ro water against waterborne molds,gotta make your own! In dwc I'd sanitize Everything take it apart & pool shock soak for a couple days. If not it'll keep coming back like herpes.you're gonna have to figure out a pool shock solution that works to run with. Pythium oligandrum kills all other of the 163 varieties of pythium then dies. It was introduced as a organic fungicide in the late 80s in America by a couple Czech scientists. The fda banned it shortly after & re classified pythium as a waterborne molds,no longer a fungus.its in Every commercial ag seed in America but companies like bayer make products to maintain it but not kill it. The toenail fungus is pythium,just saying.It keeps farmers yields down & keeps them dependent on synthetic fungicides,keeps your body loaded with fungus too because you eat it daily! I found that cleaning Everything like a usda food processing facility, regularly for a few months is the only way to kill it off. Pool shock
