+1 BettaPonic's comment
1st choice:
Always have germination with rockwool, but I am a small scale gardener. I love it for the control: ph and masterblend. I think the MB fert at 5.8 ph makes a huge difference.
2nd: 50/50 coir and pearlite. Quality coir is not expensive for the volume you get and pearlite is cheap. Usually pot up into this mix from rockwool,
hempy cup (don't let the marijuana info get to you, the info is solid) to hempy bucket or earthbox
3rd: Straight DE. Dependable, roots love it.