Fro5tyanswered grow question 3 years ago I was changing the water. It was falling to slow in to my RDWC. I putted some buckets in by hand and the tops have gotten upright in 15 minutes. Roots look fine. Maybe the airstone didn’t do enough work in that one bucket, with the water so low. I think that was it.
That white stuff is sawdust. It was the transporter for the phyto-mites I released a couple of days ago.