What are the soil requirements for growing Clivia?

Soil: The native habitat of Clivia is under the large trees of high-altitude forests in southern Africa, where its roots grow into leaf litter layers that have accumulated over many years. For Clivia cultivation, a loose, fertile, neutral or slightly acidic humus soil should be used. The growing soil can be mixed from 65% humus soil, 20% clean sand, and 15% fine stove ash. The relative humidity of the soil should be around 40%.