The pre mixed dirt that already has all kinds of nutrients. The most popular ones are like FoxFarms ocean forest and stuff. They are good, but in my experience its too much for the little girls, and I started actually using mixes without the nutes like Pro-mix seed starter for my clones and seeds. If I wanted to keep things simple, then I would switch to the hotter soil after transplant and not add any nutes for another month as indicated on the packaging usually. I usually mix these name brand type soils in with regular peat/perlite to add a little nutrient variety to my dirt once I have a stable rooted girl. Since I use nutrients, I actually prefer to use a base that has little to no nutrients, so I can better know what the plant already has or not has been feeding on, and that can help me diagnose issues.