Your thread is very educational and you dogs are really cute:)This size plants with such small containers you are showing,i find that amazing!:)I have one question about mixing your soil.Don't you wet the mix a little before using it?When I mix my soil I wet it,i think the roots make contact with the medium easier(also the ingredients make contact with each other but these are my thoughts,not something scientific,or may be it is?!) that way and seems to me the first watering is easier when the soil is already with a little moisture in it.Even leave the ready mix for 24 hours before using it.Here I see it is not nessesary,i'm just doing it:)A s far as I know perlites could be dangerous for breathing(I guess you know about that,be carefull with it),this dust from it so I wet it when I open the package:)That way the dust can't fly all over the place and get in my nose or lungs.:)