pwelfan, thanks for that 2nd video. Though not precisely scientific, these videos seem to show that the purported "best" bonsai components don't actually perform as magically as some profess. Maybe there's a balance of good and bad traits that make great bonsai soil that can't be exactly quantified. My basic theory about bonsai ( and most other controversial subjects) is ......if it works.............it WORKS...........PERIOD............end of discussion. Don't care if it's not "supposed" to work. If it does......it does.