The #4 is what I see a lot of growers using. Hopefully, you won't have salting problems anyway, but soil lightness is a good quality. REad the why I shoudl re-pot thread in the FAQs too, whcih will help you avoid the most common pitfalls of soilless growing.

I can't stand when sites stick their catalogs in .pdf... my Adobe likes to crash my browser It's a lot better since switching to FireFox but still loads up slower than molasses in January.