Akadama is not recommended in areas of extreme cold where trees are left outside. Akadama breaks down and becomes fine particles which interferes with soil drainage.

All about akadama  by Bonsai Tonight

BSOP Series: Soils by Bonsai Mirai  New 09-03-2019

Feeding, Substrate and Watering – English by Walter Pall

Life Without Turface…  by  crataegus Bonsai Note: Akadama may not be the best thing to use in a cold environment because it will break down rather fast when it freezes. Turface would be the best thing to use in Colorado along with Pumice, Scoria and a little mushroom compost.

Soil Sifting Rolling System by IBC Forum Member