Did you feed your plants any nutes during veg? Assuming not, I would be very careful when adding additional nutrients to soils with added food. Seeing as the mix you have is higher in N than PK, you could introduce a flowering food with a higher PK value. You may already be aware, but flowering plants need less N and more PK, whereas it's generally the opposite during veg.
But I must STRESS the point to be VERY careful if you choose to add bloom food as you do not want to burn your babies during this already stressful period of flowering. If you do choose to do so, start with (at the very most) 1/4 dose and observe for a few days. Work your way up as you feel comfortable.
HAPPY GROWING + GOOD LUCK!