Which ProMix? ProMix product line has several versions with/without additional ingredients, but I believe all contain wetting agent to help with the hydrophobic peat that may or may not be considered organic. (There IS a rather expensive ProMix Ultra? Professional? -- *Potting Mix* -- That is labeled organic and contains fertilizers)
But most of them don't contain any fertilizers and tends to be acidic from the peat moss, so needs a little lime to buffer it. It's good for starting and sprouting but needs dilute fertilizer once true leaves start to grow. I'm using ProMixBX (added beneficial mycorrhyzae) with a bit of Dolomitic lime and vermicompost to start the seeds, then uppoting to a mix with more vermicompost, added fertilizer, Dolomitic lime, and other ingredients depending to kind of plant.
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