How To Make Tap Water More Like Rain Water

Rainwater is far better for your plants than tap water, as it has higher levels of nitrogen that help your plants grow. Tap water contains contaminants that can burn your plants, but if it hasn’t rained for a while, how can you make tap water healthier for your plants? 

To make tap water more like rainwater, leave your water out so the chlorine dissipates and the salts settle. Boiling the water and using dechlorination tablets or other filtration helps remove chlorine and fluoride. Adjust the pH value, so it’s less alkaline, and add manure liquid for nitrogen. 

Removing the chlorine, fluoride, and excessive salts will go a long way in making tap water more like rainwater. Adding liquid manure helps add nitrogen as well. This article explains how to do this in more detail, so read on! 

1. Let the Tap Water Sit in the Sunlight

Setting water out into the sun has multiple benefits. In fact, some water purification technologies rely on solar evaporation to make water drinkable. The UV light in sunlight helps disinfect the water by killing off several microbes that might be harmful to plants. 

However, when it comes to making tap water more like rainwater, letting it sit in the sun is especially useful. Chloramines are used extensively for disinfection in swimming pools, tap water, and even drinking water. However, a concentration of chloramines is harmful to plants. 

Letting the water sit out in the sun helps the chloramines evaporate and eventually dissipate into the air. Removing chlorine through evaporation is less technology or labor-intensive than any other method of removing chloramines from tap water. 

It is important to note that this method will not remove all chloramines, but it does help decrease the concentration.  

Additionally, setting the water out to sit for about 24 hours also encourages the sedimentation of salts and other particulates in your tap water. These salts and granules settle at the bottom of the container, giving you water that’s purer and better for your garden, just like rainwater. 

2. Boil the Water

Boiling water is another way to use heat to remove chlorine from your tap water and make it safer to use in your garden. Some of the free chlorine in the tap water will evaporate when boiled and escape as a gas into the atmosphere. 

To boil your water correctly, bring it to a rolling boil and let it bubble away for at least 5 minutes and up to 15 minutes to let all the free chlorine dissipate. Let the water cool before using it to protect yourself and your plants from potential burns.

Boiling water is also a great way to fix your tap water and make it softer, like rainwater. Tap water can be ‘hard,’ meaning it has a high mineral concentration. Using too much of this to water your plants can lead to a mineral build-up in the soil that affects plant growth, 

Salts like calcium and magnesium are affected by the heat of the water and will sediment along the bottom and sides of the pot you’re using to boil tap water. Effectively, boiling your water will reduce the concentration of these minerals and make it safer for your plants. 

While setting the water to rest in sunlight and boiling are relatively easy, you can only remove so much of the chlorine and salts present through these methods. 

You’re also limited by the size and number of your containers. While boiling tap water is okay for a few plants, if you have a full-sized garden, you need more efficient ways of removing chlorine and salts to make your tap water more like rainwater.

Read this article to learn more about boiling tap water for your plants: Should You Always Boil Tap Water Before Watering Plants?

3. Use Dechlorination Tablets or Liquids

Dechlorination tablets are typically used for removing chlorine from wastewater before it’s released into natural water bodies or other systems for further processing. The tablets are a way of using chemical additives to remove chlorine from your tap water. 

Another common usage of dechlorination is in aquariums, where the water needs to be amended to keep the fish healthy. 

Sodium sulfite in crystal form is commonly used in wastewater management systems, but you can use tablets that are easier to get ascorbic acid, commonly known as Vitamin C. 

Ascorbic acid is known for being easy to use without affecting the other properties of the water in a significant way. 

The Vitabath Vita-C Effervescent Vitamin C Dechlorination Tablets available on are organic and safe for the environment. You can easily use them to dechlorinate your tap water and make it more like rainwater. The package comes with 100 tablets, and it is both effective and good value for money. 

4. Pass the Tap Water Through a Carbon Filter

Carbon filters use activated charcoal to remove chlorine from tap water. They are the most effective way of removing chlorine as the activated charcoal absorbs most chemical additives in the water, thereby purifying it. 

However, activated charcoal only works on chlorine and organic contaminants from water. It is ineffective in removing salts or minerals like lime from water which contribute to water hardness. 

If your tap water is not hard, and you only need to worry about the chlorine, then passing your water through a carbon filter is a great way to make tap water more like rainwater. In contrast, if tap water is hard and has mineral deposits, you will still need to set it out or boil it to make it softer before use. 

5. Use a Water Softener or Peat Moss

As we’ve discussed, softening water is an important step to make tap water more like rainwater, as rainwater contains lower mineral concentrations and is purer than tap water. 

Water softeners like potassium chloride remove calcium and magnesium ions from the water. The softeners use an ionic exchange to replace calcium or magnesium ions with potassium ions.

The softeners are especially effective as they remove nearly all the calcium or magnesium from the water. Using these softeners in combination with filters like greensand can help improve their longevity.

Peat moss is also a good way of softening water and reducing calcium concentration. Sphagnum peat has demonstrated that it’s effective in removing calcium from the water and is also good at acidifying the water slightly, which helps to balance the pH of tap water as well. 

However, I recommend you be careful if you plan to use softened water on your houseplants. While it is more like rainwater, watering with softened water can lead to salt build-up, eventually killing your plants. Click on the link to learn more about the topic: Can You Water Houseplants With Softened Water?

6. Distill the Water

Distillation is the best way to remove all contaminants from your tap water, making it as pure as possible, which makes it more like rainwater. 

The distillation process involves boiling the water till it evaporates, so all contaminants are either left behind or dissipated into the air. The evaporated vapor is contained and condensed back into the water, leaving behind pure water. 

While distilled water is pure, it is not exactly rainwater, as rainwater does have some minerals in concentrations that plants can use. Therefore, using distilled water is not recommended for long-term use as it will deprive your plants of the necessary minerals and nutrients over time. 

7. Adjust the pH Value

The pH value of good rainwater is about 5 to 5.5, which means that rain is slightly acidic. In contrast, the pH of tap water is around 6 to 8, which makes it more alkaline. To make your tap water more like rainwater, you must adjust the pH value and bring it lower

Be careful that you don’t bring the pH value below five, or you’ll end up with the pH of acid rain, which is detrimental to plants

One of the easiest ways of adding acidity to water is to use a very diluted vinegar solution or lemon juice. These will lower the pH without harming your plants. 

8. Mix Manure Liquid With the Tap Water

Manure liquid or manure tea is a great way to add nitrogen to tap water. As I’ve mentioned earlier, rainwater contains nitrogen in the form of nitrates. To make tap water more like rainwater, you can add liquid manure or even compost tea to the tap water. 

While the nitrogen in manure or compost is not as easily used by plants as the nitrates in rainwater, it will still supply the nutrient boost necessary for plants to grow. 

Dilute the manure liquid significantly before you add it – you can use as little as one part manure liquid to 20 parts tap water. Using too much will hurt your plants and over-fertilize them, so use the liquid sparingly and occasionally. 


To make tap water more like rainwater, you must dechlorinate it and remove salts like calcium and magnesium from it. You also need to adjust the pH value to make it more acidic and add some nitrogen through manure or compost to give your plants a nutrient boost.

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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