You're getting a lot of good information on Foxfarm Ocean Forest Soil Mix....

Give a look at their site FoxFarm Fertilizers


All of the additives are added for a great balanced soil......
Some say it's too hot for seedlings and transplants straight to soil, but Ive had success with both and gardens from germination to harvest.

I tweak my soil after transplants now with a few additives, but the strains I use can handle that.

...as a basic blend
.....I use it 3;1 with perlite and a small amount of vermiculite.
It's a great soil and one of the best....a bit pricey but great.
They also have a red bag that's outstanding for starting seeds too.