I'm using PPS-Pro and have really been struggling with how much CO2 I should use in my aquariums. The SOP for PPS-Pro is 1 bps. I can't seem to be able to make that work. I would really like to grow HC and everything I've read about HC says that not having enough CO2 is a common reason for failure with the plant. I believe my circulation is good, I can see things being blown all over. I'm at 1.5 bps right now but am considering bumping the flow up. I'm curious if other people using PPS-Pro and 1 bps have been able to grow a lawn of HC. If so, I'll start looking into other possible factors.