The downward clawed leaf tips indicate over feeding and the more gentle curve of the leaf from back to front indicates over watering or oxygen shortage. So I'm with Vostok. Good to know your ph levels as well but often not an issue with soil. I also recommend knowing your source water ppm and nute ppm.
I might not do flush just yet. If the soil is saturated, get a fan on it and let it dry out, then water hard enough to get some decent run off. I'd flush if that didn't work.