normal water has an ec of 400 ppm .... I use cane ...

Hey @shantibaba! You can give them more N. On the first 2-3 weeks of flowering they will be on a stretching period so they will need big quantities of N. You can also check your output water (after watering of each plant) meets your EC. For example, you have 400EC water, then you add enzumes, aptus root and biobizz bloom (lets say it goes around 1000EC). This is your input EC. Afther watering the plants, take some residual water and check the EC. If it's beyond your initial EC you are overfertilizing the plant (wich is not the case right now). But if your output EC is below your initial EC you are underfertilizing them (wich I think is the problem here). Hope I helped you!