Hi i'm new to this forum. I bought my 1st bonsai in early spring 2014 & after doing some basic research I was hooked. Now I have 13 trees. I stumbled across this forum while researching some problems with a Fukien tea. At some point I ended up on the post " container soils - water movement and retention " by tapla. Since I was already researching bonsai soils the gritty mix mentioned in that post sounded like a good place to start. after reading so many other opinions,ideas & recipes of what a bonsai mix should be. Although it is simple the ingredients have proven to be hard to come by ( except online ). After a couple of months of searching I am happy to say I found some crushed granite. I also found a supplier of Turface MVP so I picked up a 50 lbs bag just last week. Pine bark fines however have been very hard to locate but today I found a distributer that carries several different sizes of pine bark mulch that according to their website looks like it might be the right stuff. I also have Haydite.Lava rock & Perlite. All of my trees are subtropical so I will have to fool around with a mixture & h2o retention. Now that I've given my basic introduction I do have a question. Has anyone ever tried using Air pots or Rootmakers as training pots to build a good lateral root structure before transplanting into a bonsai pot? Sorry for the length of this post I've been following this site for about 4 months & finally joined today.Thanx for reading & your feedback. ( maybe this should have been posted under discussion rather than image sorry.)