Hey hommie I really hope everyone that’s following this post still is haha two years a little too late. But my dwc setup is doing this and everything runs fking perfect. From water to nutes to the final product! However like you I was super curious why this was happening so I took my hydroton balls out and notice my water level was too high! My rock wool has been soaking for the last three weeks and creating a sludge although my first full dwc grow I had this the plant did good but did banana at the end. Makes sense tho with I assume root rot/sludge idk what it’s called but I bet that’s your problem! listen I’m not on here much so please anyone that still sees this and wants to chat I’m on IG @carlos_the_farmer so please follow me and DM me and let me know if you seen this lol. Peace peeps

The sludge got worse from there. It said to remove the infected parts. It was the whole root up to the stalk. So I did. My first grow. It’s already stated to grow new roots.