although different species of carnivorous plants have different cultivation requirements in terms of sunlight, humidity, soil moisture, etc., there are commonalities. most carnivorous plants require rainwater, or water that has been distilled, deionised by reverse osmosis, or acidified to around ph 6.5 using sulfuric acid. common tap or drinking water contains minerals (particularly calcium salts) that will quickly build up and kill the plant. this is because most carnivorous plants have evolved in nutrient-poor, acidic soils and are consequently extreme calcifuges. they are therefore very sensitive to excessive soil-borne nutrients. since most of these plants are found in bogs, almost all are very intolerant of drying. there are exceptions: