fertilization

Hey everyone, i recently flipped the switch to 12/12 and my plants started the flowering stage. Since before I flipped the switch I transplanted into new soil and bigger pot. My question is, when should I start feeding it blooming nutritions? Cheers

I went away for the week and before i went i gave my plants a good dose of fertilizer, but then the following 3 days were pouring rain. Is this photo a pic of over fertilization or just to much water? Also my leaves are standing up and i think this means that they are trying to dispense water...