Pro: Tap water has added minerals in it, so you can worry less about fertilizing your plants. However, different water has different minerals and chemicals and you may want to test to make sure it's what your plants need.
Tap water and distilled water may keep your plants growing, but each contain chemicals like iodine and chlorine (often found in tap water) which can prevent the plants from reaching their full potential.
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.
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.
Filtered water works best for your plants
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.
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.
Pro: Bottled water can be a great alternative to tap water, if the local water is not safe for plants. If bottled water is the easiest option for you, try to use bottled spring water as it contains natural minerals that help plants grow.
Some swear by the method of letting their water sit for 24 hours so that the chlorine in the glass or pitcher will off-gas. Letting the tap run for awhile is not likely to remove any sizable portion of chlorine, unless one were to then let the water sit overnight before consuming it.
Using distilled water for indoor plants provides a safe and impurity-free source of irrigation that can prevent any toxicity from chemical or mineral buildup. It's also free of contaminants like bacteria.
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!
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.
Does Boiling Water Remove Chlorine? Yes, boiling water for 15 minutes is one way to release all the chlorine from tap water. At room temperature, chlorine gas weighs less than air and will naturally evaporate off without boiling. Heating up water to a boil will speed up the chlorine removal process.
The tap water in most areas is not safe for plants, since it contains chlorine and other chemicals that can be harmful to their health. To make your tap water safe for your plants, you may need to add a water filtration system to your home that can remove chemicals or find another source of water for your plants.
Rain/Melted Snow: Rain is by far the best type of water that you can give your plants. It is full of minerals that are necessary for plant growth, and will make your plants grow bigger and healthier than any other type of water.
As the theory goes, soaking banana peels releases nutrients like potassium and calcium into the water, which creates an inexpensive, homemade liquid fertilizer.
“If you don't give them moisture, their leaves will dry out. If you want new foliage and growth, you need to mist them.” Many houseplants come from subtropical and tropical regions and need a “relative humidity of at least 40 percent,” according to “Reader's Digest Success With House Plants.”
In side-by-side comparisons, plants watered using distilled water tend to grow faster and stronger than those watered with tap water. We find it the “Best Water for Indoor Plants.” Plants watered with distilled pure water usually produce more leaves and grow more vigorously.
There is no harm in drinking water left overnight if it is stored properly. Always cover the water kept in a glass or open container. Never put your mouth to the bottle and if you have, finish the entire bottle in one go. Do not leave the water bottle in your car.
Since our environment is full of dust particles and pollutants, the glass of water will become contaminated if it is left uncovered all night. However, it is safe for a healthy person to drink water that is left overnight if it is stored properly.
Bottled water can have an expiration date, though it's legal in the US to sell expired water. Bottled water's expiration date warns when leached chemicals will begin to affect the water's taste. Drinking expired water probably won't harm you, especially if the water was stored properly.
Bury the bottle upside down close to a plant so that the holes lie about four inches (10cm) below the surface. This makes watering so much easier because now all you have to do is fill the bottle up then move on to the next plant.
The best time to water plants is in the morning or evening.
Morning watering is actually preferable to evening watering as the plant has time to dry before the sun goes down. At night, water tends to rest in the soil, around the roots, and on the foliage, which encourages rot, fungal growth, and insects.
Not only does boiling water remove impurities, but it also kills off any pathogens that could harm humans or animals if consumed. So, by boiling already distilled water, you're increasing its purity even more, creating a safe and happy environment for your indoor and outdoor plants to flourish.