Providing water that is safe for carnivorous plants requires a little research. Water from your faucet may be perfectly fine, but it may have a detrimental effect on the health of your plants.
Not all water is the same
Using tap water for carnivorous plants in many cases isn’t a good idea. Tap water contains salts and chemicals (also called Total Dissolved Solids or TDS). While harmless to humans, some of these salts and chemicals can have detrimental effects on sensitive carnivorous plants, causing root burn, leaf browning, wilting and eventual death of the plant.
The amount of salts and chemicals in tap water is measured by parts per million (PPM). The PPM of tap water can vary depending on location but often falls between 100 and 400. Most carnivorous plants can tolerate a PPM range anywhere from 50 to 140, but the lower the number the better. If you are considering using tap water for your plants, buy a TDS Meter to check your PPM first. It’s also important to note that if your PPM is in the upper end of the “safe” range, flushing soil and trays regularly with fresh water is a good idea to help prevent mineral buildup.
Source: “What is TDS?” HM Digital
Rain and stream water
Rain or stream water can be good and inexpensive alternatives to use for carnivorous plants, if the plants are outdoors. Using rain or stream water can have downsides for indoor plants though. The main ones being possible contaminants like algae, bacteria, fungus and plant pests. Yes, even rainwater may contain small amounts of these! Exposing indoor plants to these contaminants is risky because there isn’t a balanced ecosystem like the one outside to keep various outbreaks at bay.
In addition, rain water tends to be acidic with a pH of around 5.6 due to interacting with carbon dioxide in the air. This may or may not be harmful to your plants but is still something to think about.
Distilled or reverse osmosis water
Using distilled or reverse osmosis (RO) water is the safest route when watering indoor carnivorous plants. The water is free from salts and chemicals and the steaming or filtration also takes care of organisms that may be present as well.
You can purchase distilled water at the store or distill it yourself. We have found a basic household distiller like this one works well for the average hobbyist. It can produce up to 6 gallons per day.
Obtaining clean water with a reverse osmosis system is beneficial if you need more than a couple of gallons at a time. This system can produce up to 50 gallons per day and removes up to 99% of chlorine, bacteria and other harmful substances in the water.
And please don’t do this!
A common misconception about distilling water is to leave tap water in a container overnight to give minerals and chemicals a chance to “evaporate”. This method doesn’t work though. Very little if any of the contaminants will evaporate and in most cases, as the water itself evaporates the remaining liquid is left even more salty.
Who knew there were so many types of water
Hopefully this article helps you determine what type of water you will use for your carnivorous plants based on your location and growing environment. If you have questions, please feel free to leave them in the comments and we’ll get back with you. Thanks for reading!