Ok
1. post pics
2. If you are in Veg and leaves are brown and falling off you either have Nutrient lockout, nutrient burn, or Nutrient deficiency.
3. Either way you would need to flush your plant( Drain it with water 3 times the size of the pot). To get rid of all the nutrients inside the soil. You have to set it over a bucket to do it.
4. Now you let it sit for a day and then feed it your Vegging formula. But you have to use PH down or Up to get the solution around 6.5-6.8 Ph for soil, to prevent a future lockout and to let the plants adsorb the nutrients.