Ok, it sounds like you are watering correctly but it may be drying down too far. An air pot is drying as much from the sides as the top so you might be going down as low as 30% moisture content. Really you should be using weight and not two inch depth as the guide as when to water/fertigate.
I would also be using a surfactant such as Yucca powder when you do water/fertigate in case some of that outer soil on the sides of the pot has become hydrophobic.
BioBizz Light will be holding your nutrients a little longer and you may want to go to a water, water. fertigate, repeat schedule.
The plant is growing rapidly also and this will use a lot of water as well.
