There are lots of water sources to choose from, including well water, filtered water, rainfall, and tap water. However, they are not all created equal, and each one has its uses.
So, can you water plants with tap water? You can water plants with tap water, and most of them will be fine. However, certain plants with long and thin leaves are sensitive to fluoride in tap water. If you add water softeners to your tap water, the salts can harm plants. Tap water with a very high pH (7.5 to 8.0 or higher) may make certain nutrients unavailable to plants.
Of course, there are ways to avoid some of the problems that tap water can present for plants. For example, you can use filters or avoid tap water altogether.
In this article, we’ll talk about the potential problems that tap water can cause for plants. We’ll also look into ways to solve the problem, along with alternatives to tap water.
Let’s dive in.
Can You Water Plants With Tap Water?
You can water plants with tap water without too much worry. Most tap water sources will not cause major problems for most plant species (especially in the short term).
However, there are some potential problems with tap water from some cities and towns. For example:
- Water pH – some tap water has a high pH, which can make nutrients unavailable to plants.
- Hard Water – this water has lots of dissolved calcium and magnesium, which raises pH. Too much of one can prevent plants from absorbing the other.
- Treatment Chemicals – this often refers to fluoride and chlorine, which are added to tap water by municipalities to kill bacteria and improve dental health.
The only way to know for sure that you have one or more of these problems is to do water testing. You can get a test done privately, or you can ask the city or town for a copy of the water report.
You can find drinking water data and reports (by state) on the U.S. EPA website.
How To Make Tap Water Safe For Plants
To make tap water safe for plants, it is necessary to address the 3 potential issues listed above: water pH, hard water, and treatment chemicals.
Let’s start with water pH.
Reducing Tap Water pH For Plants
Tap water often has a high pH when it comes from rocky areas with lots of limestone (calcium carbonate). Calcium dissolved in water increases pH (the same goes for magnesium dissolved in water).
Adding tap water with high pH to soil will raise pH over time. You can see how soil pH affects nutrient availability in this chart from Research Gate (in particular, iron and boron start to become less available as pH rises from 7 to 8).
Many fertilizers will lower pH when dissolved in water (that is, they will make the water more acidic). This can counter the effect of calcium and magnesium in hard water.
You can either do a soil test yourself or send a sample to your local agricultural extension office for testing. You can learn more about soil testing in my article here.
Addressing Hard Water Problems In Tap Water (Water Softeners)
Hard water can be bad for plants, and it can corrode metal pipes. It can also leave white or gray deposits when heated.
A water softening filter can address these problems. According to the Penn State University Extension, this filter works by replacing calcium and magnesium ions in hard water with sodium ions.
One disadvantage of water softening is that the water now contains sodium. This salt can harm plants in high concentrations.
Remember: the more calcium and magnesium that is removed by water softening, the more sodium is added to water.
Addressing Treatment Chemicals In Tap Water
There are two main treatment chemicals added to tap water by cities and towns:
- Sodium hypochlorite (a form of chlorine) – this is often added to tap water to eliminate bacteria to safe levels. Chloramine (a derivative of ammonia) may also be used for this purpose.
- Fluoride – this is often added to tap water to improve dental health.
Chlorine & Chloramine In Tap Water
According to the University of Minnesota Extension, most plants are not very sensitive to chlorine in its various forms. In fact, even beneficial bacteria in soil will recover quickly from watering with tap water that contains chlorine.
According to the Colorado State University Extension, most tap water does not contain enough chlorine to kill soil bacteria any deeper than half an inch. Even more impressive is that the soil bacteria population returned to pre-chlorine levels in 2 days.
Does Letting Tap Water Sit Remove Chlorine & Chloramine?
Letting tap water sit removes some chlorine – but probably not all of it. Usually, it is recommended to let tap water sit out in an open container for 24 hours to allow some chlorine to evaporate out of the water and into the air.
Letting water sit out will also allow it to approach room temperature. This is helpful if the water is coming out of the tap very cold, which can delay seed germination or shock warm-weather plants.
On the other hand, Tap Score suggests that chloramine (an alternative to chlorine) cannot be removed from water by evaporation. Instead, you will need to use active removal, like a catalytic carbon filter.
Does Letting Tap Water Sit Distill It?
Letting tap water sit does not distill it. There will still be a number of dissolved solids in tap water after it sits out, including:
- Calcium
- Magnesium
- Iron
- Heavy Metals
However, you can buy distilled tap water or make your own. CNET has an article here on how to make distilled water.
Fluoride In Tap Water
Some plants with long and thin leaves are sensitive to fluoride, including:
- Spider plant
- Easter lily
- Dracaena
- Peace lily
- Parlor Palm
- Prayer Plant
- Freesia
After enough time and exposure to fluoride in water, the leaf tips of these plants will turn brown.
To remove fluoride, you have two options:
- Flush the soil with rain water or bottled water. (This will remove some of the fluoride and hopefully reduce it to acceptable levels.)
- Install a reverse osmosis system (these systems can cost thousands of dollars).
According to WebMD, EPA guidelines state that tap water pH in the US can range from 6.5 to 8.5.
Water with a pH on the high end of this range this will cause problems for plants. For example, a high pH it will limit the availability of iron and other nutrients.
You can read this article to see what iron deficiency in plants looks like, and this article to find some fertilizers that are high in iron.
Is Filtered Water Good For Plants?
Filtered water is good for plants because it contains fewer harmful contaminants than unfiltered water. However, remember that filtering can also remove minerals that plants can use for growth.
There are some different methods for filtering water. Two interesting ones are reverse osmosis and sand filters.
Reverse Osmosis Water Filter
Desalination plants use reverse osmosis, which moves water from an area of high concentration to an area of low concentration. According to the CDC, reverse osmosis systems will remove common contaminants from water, including:
- Protozoa
- Bacteria
- Viruses
- Chemicals (such as sodium, chloride, copper, chromium, and lead)
Reverse osmosis can also reduce (but may not eliminate):
- Arsenic
- Fluoride
- Radium
- Sulfate
- Calcium
- Magnesium
- Potassium
- Nitrate
- Phosphorus
Of course, some of these substances (such as nitrate) are helpful for plant growth. So, you may just end up adding some of them back into the soil with a fertilizer.
You can learn more about how reverse osmosis systems work from Fresh Water Systems.
Sand Based Water Filters
A sand filter moves water through sand to clean it. The water molecules can move through the sand, but the large contaminant particles cannot.
According to the CDC, a slow sand filter is a sand filter that households can use to clean well water or tap water. Slow sand filters can remove:
- 99.98% of protozoa
- 90% to 99% of bacteria
- Some viruses
You can find sand filters that are used for pools and ponds, such as this Hayward Pro Series Sand filter from Doheny’s. These filters will remove some of the contaminants from well water before you use it in your garden.
The Michigan State University suggests that soil will also work to filter out contaminants from water (although protozoa, bacteria, and viruses may remain).
Do Plants Grow Better With Tap Water Or Distilled Water?
If your tap water has a high pH (7.5 to 8.0 or higher), then you are probably better off using distilled water for plants. As mentioned earlier, a high pH can prevent plants from absorbing certain nutrients (such as iron).
In theory, distilled water should have a pH of 7.0 (neutral), since there is nothing dissolved in it. However, carbon dioxide will dissolve into distilled water on contact.
This will create carbonic acid, which can lower the pH of distilled water to 5.8 within hours after distilling.
If your tap water has a lower pH (less than 7.5), it is probably fine to use it for watering plants. After you mix in fertilizer, it will lower the pH of the tap water further.
The exception would be if there are any heavy metals or contaminants (protozoa, bacteria, or viruses) in the tap water. This can happen due to failure at a water treatment plant or a damaged pipe.
In that case, you shouldn’t spray any part of the plant that you harvest (for example, the leaves on lettuce or spinach, or the fruit on tomatoes or peppers.)
Do Plants Grow Better With Tap Water Or Bottled Water?
Bottled water still has some minerals in it (which improves flavor – you wouldn’t like distilled water!) However, the mineral levels are not as high as hard water that has lots of calcium or magnesium dissolved in it.
Tap water still has some minerals in it. However, there is always the potential for high pH, hard water, and contaminants (as mentioned earlier).
For that reason, you are probably better off watering plants with bottled water if you can afford it. Another option is to consider a water filtration system, which could end up saving you money in the long run.
Do Plants Grow Faster With Tap Water Or Salt Water?
Most plants will grow better with tap water. However, there are some exceptions.
For example, some plants can tolerate salt water, and some are even adapted to grow in it. According to Clemson University, plants such as rosemary and Mexican sunflower will tolerate salt and can grow in coastal regions.
If you are growing salt-tolerant plants or acid-loving plants and your tap water has a high pH, you might be better off using salty water (such as water that has been treated softened).
What Kind Of Water Should I Use To Water My Plants?
One of the most natural sources of water for gardening is rain water. In addition to allowing the rain to fall where it may, you can catch rain water in a barrel for storage and later use.
Just be sure to avoid mosquito growth by covering the water barrel after a rain (remember to uncover it before rain to harvest the water).
Well water can also work for watering a garden. However, some of the same contaminants that appear in tap water can also show up in well water.
You can learn more about using well water for plants in my article here.
Conclusion
Now you know about what potential problems tap water can have for plants. You also know how to address these problems.
I hope you found this article helpful. If so, please share it with someone who can use the information.
You can learn more about how to water a garden (including when to do it) here.
You can learn how to set up a self-watering garden here.
If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here. Enjoy!
~Jonathon
FAQs
Can You Water Plants With Tap Water? (& Other Watering Tips) | GreenUpSide? ›
Tap water, especially when it's not distilled, contains several chemicals that are bad for you and your plants. Your tap water contains things, like lead, chlorine, and pathogens. These are harmful to your plants and will cause problems when you're consistently watering them with this tap water.
Is tap water OK to water plants with? ›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.
How long do you have to leave tap water out before watering plants? ›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.
How do you make tap water safe for plants? ›A: To make tap water safe for plants, you will need to remove the chlorine and other minerals. You can do this by leaving the water out in an open container for 24 hours. The chlorine and minerals will evaporate, leaving the water safe for your plants.
What plants do not like tap water? ›Plants with long, narrow foliage such as Spider Plant, Peace Lily, Dracaena, and Prayer Plant can be negatively affected by tap water high in fluoride.
What is the best water to water plants with? ›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!
How long does it take for chlorine to evaporate from water for plants? ›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 letting tap water sit remove chlorine? ›Because chlorine is considered to be extremely volatile, it will evaporate without much issue. If you don't want to spend money to get rid of chlorine in your water, the chlorine will eventually evaporate if you simply leave the water to stand.
Is boiled tap water better for plants? ›Boiled and cooled water is often recommended for houseplants and garden plants, as it is free of most pollutants. Boiled water can also help reduce the build-up of salt in the soil, naturally occurring with regular watering.
Is tap water better than rain water for plants? ›Can you shed some light on why rainwater is better than tap water for plants? Answer: Rainwater tends to be way more pure than tap water, city or well. Rain contains few salts, minerals, treatment chemicals or pharmaceuticals often found in municipal tap water.
Which plants are most sensitive to tap water? ›
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. It is taken up through the soil and accumulates in the leaf margins, creating brown marks (necrosis).
Can you water plants with coffee? ›It's okay to water plants with leftover coffee or to add coffee grounds to the compost pile but learning when and why to use coffee in the garden will protect your plants. Only use black, unflavored coffee with this method to offer plants a source of nitrogen which can fertilize certain indoor and outdoor plants.
What kind of water makes plants grow faster? ›The rainwater and bottled spring water are great at helping plants grow, but the sugar water and salt water actually hurt growing plants. Tap water and distilled water may not hurt the plants, but you'll notice they don't grow as tall and proud as the plants that were fed rain and spring water.
What do you add to water before watering plants? ›The quickest way to dechlorinate tap water for plants is by adding a dechlorinator solution or using a water conditioner that neutralizes chlorine and chloramines.
What liquid makes plants grow faster? ›Carbonated Water
Thus, feeding the plants with water that has CO2, helps the plants to grow rapidly and greener. Carbonated water contains many macronutrients such as oxygen, hydrogen, phosphorus, carbon, potassium, and sodium; all of which are advantageous for the growth of plants.
While a sudden change in the taste, odor, or color of your water can indicate that your filter is failing, high levels of important contaminants, such as pathogens, arsenic, lead, and nitrates, are not observable to your senses. The only way to truly know whether or not your filter is working is to test your water.
What is the cheapest way to purify water? ›Boiling water is the cheapest and safest method of water purification.
Is tap water safer than bottled water? ›Overall, both tap and bottled water are considered good ways to hydrate. However, tap water is generally a better option, as it's just as safe as bottled water but costs considerably less and has a much lower environmental impact. Plus, with a reusable water bottle, tap water can be just as convenient as bottled.
What can I use if I don't have distilled water? ›Filtered water is one solution. Filtered water starts out as plain tap water. You may already have filtered water in your home by way of a whole-house filtration system, a faucet filter or a water filtration pitcher (you can even get a filtered water bottle).
Does boiled water replace distilled water? ›No, they aren't the same. Boiled water is simply water that has had the temperature increased until it reaches its boiling point. This kills a host of bacteria that can make a person sick. Distilled water is water that has been stripped of all impurities, including minerals and microorganisms.
Can I use boiled water instead of distilled water? ›
At the same time, boiling does not have an effect on other impurities like minerals, and so these remain in the water. Therefore, while boiled water can't be used in the ways that distilled water is used because of its mineral content, it can be consumed.
What are the symptoms of chlorine deficiency in plants? ›Chlorine Deficiency
On other plant species, the most commonly described symptom of Cl deficiency is wilting of leaves, especially at the margins. As the deficiency progresses and becomes more severe, the leaves exhibit curling, bronzing, chlorosis, and necrosis.
A: It's a waste, but fresh pool water is not safe for irrigating plants. It's because the chlorine in pool water is very toxic to plants. If the chlorine level is low enough, it's possible to use it. Chlorine is a great disinfectant and used for killing human pathogens associated with food crops such as E.
How do you Dechlorinate water quickly? ›By boiling water on the stove for 20 minutes, the water will degas and chlorine will evaporate. Before you use the water in a ferment or any other fermentation-related activity, ensure it cools to room temperature first.
How do you Dechlorinate tap water naturally? ›You can remove chlorine from water naturally by boiling water, letting the water sit at room temperature overnight, or using a filter made from natural media, like an activated carbon filter. All of these methods are cost-effective and chemical-free.
How long can you store chlorinated tap water? ›Replace water every six months. Keep containers in a place with a cool temperature (50°F –70°F). Keep containers away from direct sunlight. Keep containers away from areas where toxic substances, such as gasoline or pesticides, are present.
Does microwaving water remove chlorine? ›The treatment effect of microwave and organic acid was better than water washing. Microwave and citric acid removed 42.9 % and 47.2 % insoluble chlorine proved by XANES analysis.
Is pasta water good for plants? ›What our experts say. Our team of gardening experts were in agreement: pasta water is a good way to save water and, provided it's not salted or seasoned, won't harm your plants. And while it might be able to offer very mild fertilization, it shouldn't be substituted for your usual house plant feed.
Is Egg water good for plants? ›You can also use water from boiling eggs, which is full of calcium your plant needs to grow. This method of watering your plants works because it acts like a fertilizer to give your plants the nutrition they need to survive. This is a great alternative if you do not have the space or time to develop a compost pile.
Do you water plants with cold water? ›Ice cold water will cause root shock, which may lead to permanent root damage, leaf drop and other problems. Allow the water to warm to room temperature before watering the plants.
What is the best method for watering plants Why? ›
It's always best to water deeply and less frequently. In the heat of the day, plants sometimes wilt to conserve moisture, but they should perk up again when evening comes. If you allow the soil to get too dry, the fine, hair-like projections on the ends of the roots may be damaged.
Is it better to water plants in the morning or the 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.
Why not use tap water for plants? ›Tap water isn't good for plants because it contains chlorine and other harmful substances that can be harmful to your plants. If you still decide to use it, let the water sit in bottles under the sunlight. The harmful substances should evaporate in a couple of days.
Where can I get distilled water for my plants? ›If you want to try watering plants with distilled water, you can purchase it at most grocery stores or make your own. You can buy a distillation kit, often found in sporting goods departments or do it with common household items.
Are egg shells good for plants? ›Eggshell Benefits
As it happens, eggshells can provide all the calcium carbonate the soil needs, which helps to lower the soil's pH level and make it more alkaline as opposed to acidic. This is incredibly beneficial for plant growth because many plants prefer to grow in soil that has low acidity.
In most cases, the grounds are too acidic to be used directly on soil, even for acid-loving plants like blueberries, azaleas and hollies. Coffee grounds inhibit the growth of some plants, including geranium, asparagus fern, Chinese mustard and Italian ryegrass.
Is banana soaked in water good for plants? ›How Does This Work? Banana peels contain lots of nutrients, including potassium, phosphorus, magnesium and calcium—all of which are needed for good plant growth. Soaking the banana peels allows the nutrients to leech into the water, and once it hits the soil, the roots grab all those sweet, sweet minerals.
Is there a plant that needs water every day? ›1. Impatiens – these flowers love the shade and make excellent houseplants. Even when they're not in bloom the glossy, shimmering leaves draw the eye. Impatiens need rich soil for optimal growth and should be watered regularly so the soil doesn't dry.
Which plant can go 7 years without water? ›Drought tolerance is one of the unique features of resurrection plants. They can survive for up to seven years without water in dormancy and lose up to 95% of their moisture content without cell or tissue damage.
What plant only needs to be watered once a week? ›Air plant (Tillandsia)
This plant is an epiphyte, which means it doesn't need soil at all. You don't ever really water it; you just mist it about once a week, and that's enough!
Is tap water or boiled water better for plants? ›
Boiled and cooled water is often recommended for houseplants and garden plants, as it is free of most pollutants. Boiled water can also help reduce the build-up of salt in the soil, naturally occurring with regular watering.
Do plants grow better with tap water or distilled water? ›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.
Is rainwater or tap water better for plants? ›It might not come as a surprise that there's no water plants love better than rainwater. Imagine your thirsty plants doused in droplets fallen fresh from the sky, their leaves expertly channeling the bounty down stalks and into the soil—right to the root zone where it is needed most.
How do I lower the pH in my tap water for plants? ›Vinegar and lemon juice offer natural ways to lower the pH of water. Add several drops at a time, using a meter to monitor changes. Remember that organic options are slower-acting, so wait an hour and measure again before showering plants.
Is bottled water OK for plants? ›Among the different types of bottled water, spring water is deemed best for plants. On the other hand, (bottled) purified or distilled water is the least beneficial for plants.
What liquids help plants grow best? ›“Similarly, white vinegar, coconut milk and banana peels are all bursting with important nutrients that can help your plants grow and thrive. “Surprisingly, even human and pet hair can be used thanks to its high levels of magnesium – so think twice before vacuuming up your pooch's fur!”
What type of water makes plants grow faster? ›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.
What is the best alternative to rainwater for plants? ›Purified water is available in a number of forms; including distilled and deionised. These waters do not contain any impurities such as minerals. Purified water is too expensive for widescale use but can be useful for plants that do best with rain water, such as orchis, when rain water is unavailable.
Does Epsom salt help plants pH? ›Derived from the breakdown of mineral rocks, Epsom salt is neutral in pH value and has no effect on soil pH levels when applied to soil in dry application or as drench.
What is the fastest way to lower soil pH in a potted plant? ›Soil pH can be reduced most effectively by adding elemental sulfur, aluminum sulfate or sulfuric acid. The choice of which material to use depends on how fast you hope the pH will change and the type/size of plant experiencing the deficiency.