My N. ventrata's pitchers are getting smaller and smaller. The plant itself is growing at a tremendous rate, about 6 inches a month vertically, but it only produces one pitcher at a time (despite having 6 growing points) and they're tiny compared to previous ones. It is producing uppers now, about 1.5"-3" tall.
It's growing in a west facing windowsill with plenty of light, 60% humidity, and temperatures in the upper 70s. The growing medium stays moist. Any idea what's going on?