That's definitely not the highest clay level known on Earth, but I am just wondering what all those white specks are. You said you had thrips? When I had them, the bites looked similar, but again it's hard to tell for sure and I had bites that looked similar from spider mites hiding under the leaves having a chomp on the poor girl. Maybe it could be dust? Eggs? My old person eyes can't tell- LOL! The bugs can absolutely stunt growth if your pH and other factors are good. I will tell you that I completely annihilated a plant once, treating it with alcohol and dish soap for mites, fixed the pH issues and it thrived, although the yield was not great, somehow the end result was good. I would personally transplant and finish it off, watering at 6.0-6.5pH water, because I am a stubborn SOB, LOL!