I had some issues early with one of the things I top dress with. I use Gnarly Barley after I listened to Clackamas Coot on a podcast a few years ago. I have been buying it from Build A Soil and then grinding it in a coffee bean grinder and top dressing. This time I got it ground and it was more like the consistency of flour. I think it would have worked better mixed in the medium. I put far too much on top and it formed a crust that water had a hard time getting through, then once it was wet, it didn't want to dry out. I yanked a bunch of it out of the pots two days ago.