Good testing, Im wondering if your cups have holes in the bottom? were they outside? I was convinced that the coated stuff would be way better, I was gonna switch to using it this year for overseeding, but now I'm skeptical, perhaps I will also conduct a test when the weather warms up around here. I also think a good test would be to leave the pots outdoors with minimal to no watering and see how mother nature plays into affect. Keep up the good work there Riggle.