I will be before too much longer. I currently expect to be dropping seeds for it in about 2 weeks.
I won't lie. I am slightly nervous about running it in RDWC. Why? Well, several slight concerns.
First, I've noticed it's turning my perlite brown. While I have no proof, I wonder if it will stain my roots? If so, it could make it more difficult to spot root issues. Also, other coloration issues with pipes and internal parts. Maybe, maybe not. We'll see.
Second is the suspension issues. This is less of a concern, I'll admit, but still a concern none the less. I think the circulation flow should keep it stirred up, but it will need an eye kept on it to make sure there isn't a buildup of sediment.
Third, and just recently added to the list, is this "scum" layer. I'm guessing from reading that it's a slimy film of sorts. If so, z7 should take care of that.
I'm not overly concerned with any of this, but they are still concerns. My revised RDWC will hold approximately 65 gallons total. The big bag of MC should last me about 52 weeks of growing (off the top of my head, as I figured 65 weeks with my slightly smaller capacity.)
Makes for about $25/grow in nutes. Next closest would probably be Jacks, which from the looks of it (with long term use, buying in bulk) would work out to $35-$40/grow. If I had to use something else? GH trio, etc? Yikes! It would be flood and drain with MC, RDWC be damed.