I used a self-mixed soil, ingredients:
-topsoil
-potting soil (from DIY market chain of french origin with biber mascot)
-Seramis granulate (like vermiculite but with a little nutrients)
-cocos fibre
-lots of soil enhancers: fish meal, rock powder, epsom salt, organic fertilizer with guano (7-4-5), horn shavings, organic potassium fertilizer, mykhorriza, sulfur powder for long term pH reduction (tap water comes at pH 8-8.5)
(there might have been other ingredients I have forgotten by now)
-topsoil
-potting soil (from DIY market chain of french origin with biber mascot)
-Seramis granulate (like vermiculite but with a little nutrients)
-cocos fibre
-lots of soil enhancers: fish meal, rock powder, epsom salt, organic fertilizer with guano (7-4-5), horn shavings, organic potassium fertilizer, mykhorriza, sulfur powder for long term pH reduction (tap water comes at pH 8-8.5)
(there might have been other ingredients I have forgotten by now)