Rainwater Vs. Tap Water For Plants – Which is better?

Rainwater differs from tap water in several ways. What sets rainwater apart from tap water is that it undergoes a natural filtration process, whereas tap water does not.

Additionally, some plants may benefit from the increased acidity of rainwater compared to regular tap water. Rainwater also differs from tap water because it does not include chlorine or other chemicals.

Tap water goes through a treatment process that includes chloramine and chlorine. Salts and fluoride found in tap water could damage the soil if consumed in large quantities.

Rainwater is the most common synonym for “soft water.” Most water has a pH between 5 and 7, making it more acidic.

Primary reasons to use rainwater to irrigate your plants:

  • Water savings by the exclusive use of collected rainwater for irrigation.

Due to the growing worry over water scarcity, this is only one of several easy strategies to reduce your water costs immediately. By collecting rainwater for domestic use, you help lessen the amount of water polluted by storm runoff.

Rainwater is ideal, but if you are in a pinch and it doesn’t rain often where you are, filtered water will do. It’s a far more secure alternative to regular tap water. Although it may be costly to set up at first, it will be a wise investment over time.

  • Its pH ranges from 5 to 7, ideal for plant growth.

Plants like to have this in their soil rather than the alkaline water found in most municipal water systems.

Long-term exposure of plants to very alkaline water can lead to problems like a mineral deficiency. While this is rarely a problem, it is important to note that the source of tap water varies.

  • It has fewer synthetic chemicals than regular tap water.

Salt deposits are less likely to occur in plant soil. If they aren’t washed away with water, they can build up and eventually harm your plants.

If not acid rain, rainwater has a higher trace mineral content from the atmosphere and may even be safer to drink.

The Difference between tap water and rain

Chloramine and chlorine are added to municipal water supplies. Expert gardeners will tell you that after 24 hours, tap water is safe to use again because the chlorine has evaporated. But chloramine has no such effect.

Heavy quantities of minerals, salts, and fluoride exist in tap water, all of which are detrimental to soil health. This is referred to as “hard” water.

It has a higher pH than rainwater, which can lead to nutrient lockout. This is where plants are unable to absorb the nutrients they are exposed to.

However, rainwater is typically considered “soft” water. That is to say, it does not include any of the minerals that might cause water spots in fixtures like sinks and bathtubs.

Water with a pH between 5 and 7 is optimal for plant growth and soil health. This is because it is more acidic than regular tap water. Plants also benefit from the dissolved nitrogen found in rainwater.

Do you need to filter rainwater for plants?

As part of a sustainable gardening routine, you can take a few easy precautions when collecting rainwater for garden use and other non-potable purposes around the house.

The most typical technique involves redirecting the flow of rainwater from a downpipe into a storage tank. At this point, filtering the water is recommended for several important reasons:

  • Water filtration systems make sustainable farming easier by filtering out large particles in the water before pumping it.
  • Without resorting to a chemical anti-algae solution, the filter will inhibit the growth of algae and sludge in the tank, keeping the water from turning “green.”
  • The process of filtration will remove any leaves or other organic matter that may be present in the water. This is beneficial because it lowers the risk of disease transmission. It also enables you to use the collected rainwater on the plants that are the most recent additions to the garden. This makes it possible to have gardening that is truly sustainable.

Do plants prefer tap or filtered water?

Avoid using tap water if you want the plants to thrive and grow rapidly and healthily. Most municipal water supplies are unsafe for plants. This is due to the presence of chlorine and other chemicals.

If you want to use tap water for your plants but want to keep the chemicals out, you may need to install a water filtering system in your home.

If you’ve gone through the trouble of installing a water filtration system in your house, it’s likely that you want the best for your entire family, including the plants. While it may be tempting to use water straight from the tap to water your plants, filtering the water first is recommended.

Plants benefit greatly from drinking filtered water for the same reasons humans do. Activated carbon filters are a good place to start if you’re new to water purification systems.

Which water cannot be used to grow plants?

Water from bottled springs or rain is ideal for plant growth, but salt and sugar water are detrimental.

The plants will not die if you water them with tap or distilled water. But they won’t grow as tall and proud as those you will water with rain or spring water, either.


It is crucial to know what is in each sort of water in order to determine which is optimal for plant life. While tap and distilled water will keep your plants alive, they will not thrive.

This is because of chemicals such as chlorine and iodine (commonly found in tap water).

Springwater and rainwater are naturally occurring and contain no chemicals that could potentially harm new plant life.

The yellowing of the leaves in plants watered with salt water or sugar water is a sign that plants can die from ingesting excessive amounts of salt or sugar.

Tap water or rain – which one wins?

The advantages of rainwater over municipal water for agriculture could encourage people to start harvesting it. Harvesting rainwater is rarely discussed beyond its potential for water conservation.

Still, there’s more to it. You can provide your plants with the required high-quality water by capturing and storing rainwater. Your plants will thank you for this!