While using water straight from the tap might seem good enough for your plants, by now we know it's actually highly advisable to put your water through a filtration system prior to watering your plants. Filtered water is not only good for you, but it's great for your plants too.
Best Water for Houseplants
Most tap water should be fine for houseplants unless it is softened because softened water contains salts that can build up in the soil over time and cause problems. Chlorinated water is also safe for most houseplants, but if you have a filtration system, that's much better for your plants.
Reverse osmosis solutions also contain activated charcoal filters that remove excess chlorine that is present in most tap water. Filtering water makes it safe for everyone in your household, including plants, people, and pets. A water filter will also remove excess nitrates, phosphates, and lead.
Run your sink into a watering can, cup, or bucket, and let it sit for a good 24 hours. This will allow chemicals like chlorine and fluoride the time to evaporate from the water. We like to have a full watering can ready to go with still water so that if our soil seems dry, we can water our plant without waiting a day.
While watering your yard plants with bottled water may be impractical, using bottled spring water for your indoor plants will make a big difference for them. To give your plants the absolute best, rainwater and bottled spring water are your best options. Any water containing sugar or salt will hurt them!
While both water sources should allow the plants to grow, the findings should be that the bottled water will provide more nutrients to the plants than the tap water.
Though tap water is considered filtered, high levels of chlorine remain in the water. It is recommended to use a filtration system to provide the purest water for your family and plants. If the budget does not permit, letting water sit out for 24-hours before watering, experts say, can also remove harmful chemicals.
If you use tap water, you may notice that your plants are not growing as tall and strong to the best of their abilities. To reduce the risk of harmful chemicals in your water, allow your tap water to sit out for at least 24 hours before using it to water your plants. This allows the chlorine to dissipate.
Some parts are particularly sensitive to specific chemicals found in tap water. Fluoride is damaging to spider plants, corn plants, prayer-plants, dracaena, and peace lilies.
In addition to creating an unsightly white crust on soil and pots, hard water can damage your plants. They can cause a buildup of salt in the soil, which then prevents your plants from absorbing moisture properly. This can then cause your plants to fail to thrive.
If you are sure your tap water contains chlorine and not chloramine, you can let the water sit for 1-5 days to allow all the chlorine to evaporate. To speed up the evaporation process, aerate the water with an air stone for 12-24 hours or boil the water for 15-20 minutes.
Collected rain is usually naturally slightly acidic, so it can help flush away the build up of accumulated substances from alkali tap water deposits in your potting soil. I just set a bucket out in my yard to collect rainwater, fresh from the sky. Fresh bucket-collected rainwater is tops in purity for plant watering.
But if you're still concerned, simply check the smell of your tap water. If you can smell chlorine, it likely has unusually high chlorine levels. You only need to fill your watering vessel with tap water and leave it for 24-hours before watering your plants. The chlorine will evaporate over this period.
Give Your Plants the Right Nutrients
You'll also want to ensure that there are no harmful chemicals in your tap water, but that healthy minerals remain. A water filter pitcher like Aquagear will remove contaminants like PFOA/PFOS, PFAS, lead, chlorine, microplastics, trace pharmaceuticals, and more.
An excess of chlorine is what contributes to brown leaf tips in sensitive plants. These plants include: palms, spider plants, dracaena, azaleas, camellias, gardenias, etc.
It is best to use a point-of-entry filter system (where your water pipe enters your house), or whole-house filter system, for VOCs because they provide safe water for bathing and cleaning, as well as for cooking and drinking. Activated carbon filters can remove some VOCs.
Filtered water is groundwater or tap water that has undergone a process to remove impurities and a variety of physical and chemical contaminants in an effort to make the water cleaner for drinking (not to mention far more refreshing).
Most plants are fine with tap water, but some are more sensitive than others. These include cordylines, dracaenas, spider plants and marantas.
R/O Water: R/O, or reverse osmosis, is a technique that is used to remove minerals and impurities from water, such as chloramine, salts, and heavy metals. This is fine to give to plants, and some prefer it because it lacks certain minerals that can cause issues with fertilizers.
The simplest and fastest technique to determine the chlorine level in drinking water is a test strip. Test strips are similar to the ones used for drug or urine testing. One part of the strip is infused with DPD or diethyl-phenylene diamine. You need to dip this end in the water for a few seconds.
The Standard and Brita Elite filters are both certified for the reduction of aesthetic chlorine under NSF/ANSI 42, meaning that they should remove chlorine to levels low enough so they do not cause taste and odor problems in your drinking water.
Vitamin C is a newer chemical method for neutralizing chlorine. Two forms of vitamin C, ascorbic acid and sodium ascorbate, will neutralize chlorine. Neither is considered a hazardous chemical.