My planted tank has an unusual problem. I have no oxygen pearls on any plants. I have pressurized CO2 through a DIY co2 regulator, flourite substrate, no air bubbler during the day, 650w pc, 135 gallons, pH=6.8, KH=7dKH, and Greg watson ferts. None of my plants will pearl. Anyone know why, or what I can do to encourage pearling?