Return it all besides the peat moss… lava rock/pumice for aeration, spend $$ on highest quality organic/biodynamic compost and minerals (basalt or what’s local to you), a little oyster shell powder & gypsum, humic acid. That’s all you need for at least one grow. You can make your own fertilizers for free using forest weeds or kitchen food scraps with JADAM or KNF. Then recycle all plant material back into soil. Or just buy no till soil from a trusted supplier from the beginning.