Keep an eye on your nute ppm`s for a fairly rapid drop that begins around the 4th true leaf stage. Its a good sign the plant is increasing its uptake of nitrogen (N), potassium (K) and calcium (Ca) prior to flowering. If you stick with the same feed regime, you`ll likely see the plant begin to strip N and K from its lower, older leaves to supplement the shortfall.
I run the same baseline of micro`s and Mg from start to finish and just increase N,K and Ca levels with additional calcium nitrate, potassium nitrate and occasionally potassium sulphate at the appropriate time.