Get a 5000K CFL or LED bulb on the end of an extension cord and hang it in your tent for taking pictures. Turn any other lights off. We need to see the natural colors of the plants to be able to determine their health.
Flushing soil is a last ditch effort to save plants that are already dying.
What you need to do is get a good soil PH probe (Accurate 8 or clone or Blue Lab Soil probe), you need to know the PH in the root zone where it counts.
See PM. I always recommend to follow vendor charts for feeding. The flushes in the chart relate to coco only.
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