Ahh thanks for the clarification, I should have read the text. I was going strictly by the picture.! A strictly sand media experiment may be in order
I've started the next experiment. I have a Cephalotus seedlings, from the same batch as the plant above, potted in a mix of 2 parts dune sand, 1 part peat, 1 part Dorset pea gravel. Dorset pea gravel is often sold in aquatic shops, so assumed to be inert... it typically isn't! It is sea polished gravel, therefore contains quantities of marine exoskeletons and possibly dolomite, both being alkaline. It fizzes well in vinegar. The soil mix should be fairly alkaline, so will be a test to see if Cephalotus can tolerate such conditions as it is often assumed that they are acid loving.
Nice thread. can't wait to see the results of your new experiment.