I was in sort of the same situation as I already had the Pro Mix Ultimate Organic. I just followed the direction on LC#2 mix and so far it's been working ok. I have no idea what the difference is between the two. I think the organic doesn't have the wetting agent and it also has a sea based compost mixed in with Mycorise. Next time I just plan on getting the pro mix peat, it's cheaper and I can control exactly what goes in the mix.