Well if the problem is fert buildup in the medium then you don't have a true deficiency....it's actually a def due to a lockout....too much crud and salinity in your medium can affect the roots ability to uptake nutes thus LOCKING things out. Abnormal ph will do the same thing.

You are much better off using the Florakleen for 24 hours than just pouring water through at this stage. I would use 10ml (2tsp) a gallon for 24 hours (watching ph constantly...it WILL shift alot) then replace the system with fresh nutes. Sorry....more water to carry.....:wtf: