Soil with gypsum

They should be kept very sunny. If they are kept outdoors during summer they must be protected against rain. From November to March there must be a winter period at 6-14°C.The plants have to be kept in dry soil. Use pure mineral cacti soil and cacti fertilizer. Humus and organic fertilizers should be avoided. It is recommended to add a bit of plaster. If necessary you can water every once in a while with Gypsum water.