Pearling is caused by high oxygen saturation in the water, not by too much/lack of co2 or anything. Massive pearling is commonly exhibited after a water change, where the oxgen saturation of the new water is already high. CO2 is not the only factor in healthy plant growth, either. It's a all a combination - of CO2, lighting, ferts, etc. If your plants are healthy, though they may not be pearling, and your fish are healthy, and you don't have algae issues, you're there.
Wylfya are you using the EI Dosing, just wondering cause you said you only dose KNO3 and Micros, how about the KH2PO4 and the K2so4
For all the hobbyist who injected co2 on their tank, try the Drop Checker its more accurate than those test kits. (Kh and Ph)