HSO - 707 Headband, by TMO

Its been a great week 2, after giving ( BPS - Bud Explosion ), the girls imediately understood the flowering had started and are going for it. 1 of the 707´s, planted in an airpot, has made me scrathch my head a few times. All the 707´s get the same nutrient solution, same ph, but the one in airpot started to turn a bit yellow, so i made an not as proff run-off reading. It showed ph 6.0 and ppm 1900, so had to pour a few litres of demineralized water on it. Why the airpot one is the only to go crazy, i do not know. the others, in fabric pots and plast pots, were spot on. ( My theory is that the airpot soil dries out sooner than the other pots, thus making the nutes less available for the plant and accumulating in the soil.)