Besides the bio Grow & Bloom, I use a free nutrient: banana peel water mix.
--> you just fill a large bottle up with banana peels and a bit of green fanleaves you took of during defoliation (fresh!). Than you fill this bottle up with water with a normal PH around 7. After around 2 weeks the water becomes yellow/brown, the nutrient is ready to use. This mix contains a boost of potassium for your girls, really helpfull for the flower phase.
Use a cup for every 1L you water.
@Chilipadi, yes just leave the peels in the water for 2 weeks. After than you can put the water in another bottle and start the progress over and over. Dont use to much if you already use other nuts. 1 cup for every 1L works fine. The fanleaves aren't a must, this is just extra nitrogen for the mix. But if you do defoliate why not use it ;)