Water quality is EXTREMELY important for carnivorous plants. Always use mineral-free water with your carnivorous plants, such as distilled, rainwater , reverse osmosis or “Zero Pitcher” water (that brand specifically). The minerals from tap water can and will burn your plants. It will not happen immediately, but will eventually cause the demise of your prized carnivorous plants.
Ideally you want the water you use to contain no more that 50 ppm (parts per million) TDS (total dissolved solids), or risk harming your plants.
TDS (Total Dissolved Solids) Measuring.
In order to verify your water is safe, I recommend getting a TDS (total dissolved solids) meter. They are rather inexpensive, and provide peace of mind that your water is indeed safe for your plant. TDS meters can be obtained a couple different ways. You can purchase one online, or you can get one for “free” with a “Zero Water” pitcher (more info below).
Distilled water can be sourced from several different ways.
It can be bought from your local grocery store, many pharmacies (for under $1 per gallon), as well as online. My local Walmart sells 1 gal of distilled water for 85¢. Amazon has both 1 gallon as well as smaller containers of distilled water as well. Keep in mind that you will usually need to buy more bottles or in bulk for this to be cost effective. Make sure the ingredients are distilled water only, and that no minerals, etc. have been added (usually to enhance taste).
You can also make distilled water at home. There are several countertop “distillers” that will take your normal tap water, and output distilled water. While the upfront cost of the device is considerably more, over the long run you will save money, as well as help the environment by not disposing of the unwanted jugs/bottles.
For example this unit is available from Amazon, and will make approx. 1 Gallon at a time.
Mophorn Pure Water Distiller (Link on Amazon)
ZeroWater Pitchers (This brand specifically)
NOTE: This applies to the “ZeroWater” brand only. Other brand pitchers, such as “Brita, PUR, and store brands” do NOT remove most, if any dissolved solids. They simply remove some minerals and chemicals to make the water taste better for drinking.
ZeroWater Pitchers remove virtually all dissolved solids, as well as other chemicals (ammonia, fluoride, etc.) from your drinking water. They provide water that in most cases has 0 TDS. While this is great for your carnivorous plants, the replacement filters can be expensive, replacing these will be determined by how much water you run through the pitcher. If you use this for only a handful of carnivorous plants it might last you a year, if you use it to make drinking water, then you will likely have to replace the filters more often. Replacement filters for this pitcher are the most expensive of all the brands, at around $15 each.
Rainwater can be gathered as simply as placing a bucket outside during a rain storm, or as elaborate as purchasing a rain barrel for larger capacity. This option obviously work better if you are in a location that get a lot of rain. Rain barrels can be connect to downspouts on your home to collect rain more efficiently. It is recommended to check your water from time to time to make sure the TDS (total dissolved solids) remains under 50 ppm (parts per million).
Reverse osmosis (RO) is a water purification process that uses a partially permeable membrane to separate ions, unwanted molecules and larger particles from drinking water. This removes all the “bad” stuff from your water, and typically will leave you with a TDS reading in the mid-teens. I have an older reverse osmosis system in my home, and I typically get between 10-15 TDS readings.
Most system have 3 filters which depending on usage will have to be replace every couple years (typically). The added benefit is that you can plumb this in your home to provide water for drinking, refrigerator water and ice, etc. This is the most costly option up front, but well worth the expense in the long run. Replacement filters typically can be sourced for around $30-$50 dollars, depending on what unit you get.
Below is a link to a unit, and replacement filters on Amazon, but most hardware (Ace Hardware) and home improvement stores (Home Depot, Lowe’s) carry these in stock as well. Many department stores (Walmart, Meijer, etc.) carry them as well, but will likely need to be delivered to your home. I suggest a home improvement store is you best bet, as you will likely need some minor plumbing fittings/accessories, and can typically find help there as well.