I'm no expert but I would have thought unless you are growing in Coco then you don't need to feed for a couple of weeks or until your seedling tells you it's ready.
Yeah I agree, I'm also growing with Biobizz nutes and Biobizz All-mix soil. I am growing 4 photoperiod plants, though the same rules apply for you as they did for me. After about a week from popping from the starter cube/jiffy pellet or small pot in your case, I would transfer them into their final pot with the all mix soil, only feeding with ph'd water for at least another week or two, let the plants establish a strong root system in their new home before starting any sort of feed. The all mix already has enough nutrients to sustain the plants for a brave while. Even when you do start feeding only use bio grow and maybe some sort of organic root stimulator and nothing more at low doses maybe quarter the recommended then gradually increase the dose as the plants grow, keeping an eye on leaf tips etc for signs of burn or deficiency. Also I wouldnt recommend using bio bloom until plants actually display flower production. When you start using it same rules apply, start low and gradually increase it, as you do this, slowly decrease your bio grow levels. Also try keep your heat at around 25 degrees in UK speak., do not let it drop too much at night, try not to let it increase so much during the day and always keep good air circulating I'm the grow room.
