Cactus soil, which is sandy in nature, is not recommended for Monsteras. It’s too dry and can’t retain enough moisture. However, if you tweak the composition a bit and add the standard cactus soil to peat moss or coco peat with compost, the new mix will be effective enough to keep the soil moist. The compost also makes the soil richer in nutrients because of the organic matter in it. Such a mix is the ideal soil for the Monstera to grow and thrive in.