I struggled with dwc till I found out about hydrogaurd, then after spending shitloads on hydrogaurd I found out about Southern ag garden friendly fungicide, same shit 1,000,000 times concentrated, literally. 1 ml is enough for 20 gallon. Beneficial bacteria handles root rot everytime for me and I grow in a wooden shop outdoors where it stays quite warm in summer. I've had luck with pool shock or uc roots for a sterile set up but for me bennies are easiest, just remember if your using tap you gotta let all the chlorine evaporate out I apply the bennies 2 days after changing water unless it's hot then I do it next day, it will not work on fresh tap