I'm as well 2 weeks into flower on coco...I love this stuff!!!! I started everything out in solo cups and then moved them into 5 and 7 gallon smart pots (they are made of the same material as a weed barrier in your yard). I am doing a drain to waste as well and I shoot for the %10 run off as well. I think Canna recommends %30, but that just seems a little over the top to me. Also Aquanaut, I was explicitly told not to flush coco with just straight water. Doing this raises your EC and also there is bacteria in the coco naturally that is septic to the plants and prevents disease issues that gets washed away with a water flush. I also water on a daily basis, and nute with every watering. Nutrients I use are Canna a and B, Rhizotonic, Cannazyme, Boost, and pk 13/14 starting next week.