theres lots of different brands. But for shop bought in a tin i cant recommend great white mycorrhizae highly enough. Im not affiliatd with them in anyway but the results speak for themselves. That alongside a root stimulant will make your roots explode. Bg roots=big buds....
Of course this coco coir not soil and you get much thicker roots generally in coco. But you get the idea
Of course this coco coir not soil and you get much thicker roots generally in coco. But you get the idea