If you are not getting water to the lower regions of the pot, it can 'crust' and not easily absorb water. Especially when underwatering. A surfactant (wetting agent) helps. I use 1/4 tsp of non-antibiotic dishsoap per gallon of water. (anti-biotic soaps will kill the beneficial bacteria in the soil)

I use the molasses on a non-nutrient day, in properly ph'd water. No real reason, other than it gives the plant something to do while waiting for feeding day. (plus, it lowers the ingoing ph a tad more, which the nutrients already do)

Was just wondering if it was placed in a dead-zone of heat, stagnant air or over-breezing. (directly in front of the fan) In a cramped space, usually the plants in the back seem to get less water.

Intake fan...? Do you have an exhaust fan too? Intake fans are usually unnecessary, unless in a tightly sealed tent, enclosure or closet, where air leaks (providing the fresh air) are non-existant.