Ok I'm on my first soil grow. I've done hydro before
So I can only report what I have experienced. I started in a mix of Miracle Grow *Organic Potting Soil (Found at Wal-Mart, and Home Depot). I mixed that with MG (Miracle Grow) Perlite. My mix was about 70% MG *Organic, and 30% Perlite. I added 1 Tbsp of "Garden Lime" per gallon of soil mix(Found at Home Depot) made by "Espoma". The seedlings in this mix did terrific.
I did two mixes of soil, b/c MG (Miracle Grow) has a very negative conotation among marijuana growers. The other soil I used was "Scotts Potting Soil". All I did was mix 1 Tbsp "Garden Lime" b/c it had about 10% perlite added already. The seedlings in that soil did not thrive. They sprouted but very slow compared to the MG *Organic.
Also the Scotts did not have enough Perlite in it, and started to sprout shrooms early on. They weren't the good kind
Eventually I replanted the seedlings into the MG *Organic mix. They improved.
The seedlings were all in 16 oz. cups for about 1 month. They ate up all the nutes in the soil. I recently transplanted into bigger 3 gal. pots w/ more MG *Organic mix. They are doing just fine right now
When I transplanted into the new soil. There is new nutes that havn't been eaten up by the plants yet. So they are doing just fine w/o nutes for now, and it's been a little over a month.
Hope this helps