Will Water Softener Water Kill Plants?

Last Updated on January 13, 2023 by Mattias

Plants require water to grow properly and produce, but when you use watering methods that aren’t favorable to them, this might cause them to die or become unable to make, so you must ensure you use the right kind of water.

So, is water treated with a water softener one of the watering methods that can kill your plants, or is it harmless to your plants? Let’s find out. 

Will Water Softener Water Kill Plants?

watering plants

Yes, it will if you use the water softened with your water softener system to hydrate your plants frequently.

Softened water contains high sodium levels, and its application on plants for a long time will cause the plants to dehydrate and lose their texture. 

The best option will be to occasionally use softened water to water plants or other watering methods that won’t hurt the plant’s growth. 

So, let’s take a better look at what soft water is, its effect on plants, and alternative ways you can use it to water your plants without causing harm to them. 

Read also: 12 Best Kitchen Faucets For Hard Water + Buyers Guide

What Is Soft Water?


Soft water, in this context, is water with a high amount of sodium and a low concentration of hard water minerals such as magnesium and calcium. 

This is because, during the water softening process, the water softener undergoes ion exchange, removes the hard water minerals from your water supply, and replaces them with sodium ions in sodium chloride. 

There are numerous benefits of softened water for you and your appliances.  

Softening water improves your house’s water quality and prevents mineral buildup in your plumbing system. 

It also increases the life of a water heater and causes your water heaters to be more efficient in producing hot water. 

In addition, it reduces the amount of soap you use and the amount of money you spend purchasing soaps and detergents.

Read also: 9 Reasons Why Your Softened Water Tastes Salty

What Are The Effects Of Using Soft Water On Plants?


Salt Buildup In The Soil 

When you use water softened through a water softener on your plants, the sodium salt builds up in the soil as time goes on.

This affects the soil quality negatively and causes the soil surface and bed to be too harsh for fresh and future plants. 

This can also be noticed when you use salt water on garden plants with little rainfall to wash them away. 

Disruption In Water Balance 

The amount of sodium in the soil is used by plants to measure the water balance level, so when there is excess sodium in the ground, the plants become unable to accurately measure the water balance, making them think the water they have absorbed is too much. 

When this happens, you will be watering your plants, but they won’t get enough water, and this could cause the plant to dehydrate and die as time goes on. 

Increase In Costs

Using water treated with a water softener to water your gardens and plants daily, and also for your household activities, will lead to your water softener working more often, which will lead to an increase in costs, as you will need to add salt to the brine tank more often and also maintain it more frequently. 

Read also: How To Add Salt To Water Softener

Can You Water Your House Plants With Soft Water?

taking a glass of water and watering a house plant

No, you can’t. A house plant is a potted plant, meaning the harm that water with high sodium salt content will do to it tends to be more than regular plants.  

This is also because indoor plants have access to rainwater as outdoor plants do, making it much easier for sodium to build up on it. 

The best solution, in this case, is to use water treated with a reverse osmosis system.

Reverse Osmosis water, also called RO water, doesn’t have as much sodium content as water treated with a water softener and can help the plant grow better. 

How To Water Your Plants Without Using Soft Water 

Untreated or Unsoftened Water 

Using unsoftened water is an excellent way of watering plants.  

With good drainage, you can also use untreated water to wash the extra sodium content in your plants away. 

However, allowing hard water through your tap, water heaters, and other plumbing system puts them at risk of limescale buildup and clogging.   

Water Treated With Potassium Chloride Salt

Using potassium chloride salt on your water softener will produce soft water free with no sodium content in it, and soft water treated using this type of salt can be used to water your plants without causing harm to them. 

Potassium is also one of the helpful plant nutrients, so using water treated with potassium chloride salt pellets on plants is fine.

And hence a salt-free water softener also does not add any sodium to your water while treating it. You can also use water treated through it to water your plants.

Read also: Can You Use Water Softener Salt To Melt Ice?

Rain Water

Rain is naturally soft and can water plants without fear of harming it. 

You can easily collect rainwater by placing a container or bucket outside your house during rainfall and using it afterward to water your plants. 

The con of this method is that it doesn’t rain all year round, and at specific periods of the year, you won’t be able to get rainwater.  

Dechlorinated Tap Water 

Chlorine is another mineral that could cause harm to your plant so before you use the water from your tap to water your plants, make sure you dechlorinate it first. 

Outside Tap

You can connect an outdoor tap directly to your sprinkler system, which you can use to water your plants if you have hard water in your home. 

You can connect a hose to the outdoor tap without passing it through your water softener or installing a bypass valve for outdoor watering. 

Bottled Water 

Though expensive, bottled water is another good way of watering your plants. 

Bottled water is pure and filtered water that won’t cause harm to your plants, but you must first consider the cost involved in using it frequently. 

Diluted and Distilled Water 

You can dilute your soft water after it has been treated to reduce the level of sodium salt in it and then use it to water your plants. 

You can also use distilled water for this purpose by using a distiller to draw out the salt from your softened water and use it to hydrate your plants.

Will Water Softener Water Kill Plants Summary

Plants do not need much sodium. They need just a tiny amount of it, so using water with high sodium content on them has a good chance of causing harm to them.

Also, note that naturally soft water doesn’t have high sodium levels and isn’t harmful to your plants. It is the soft water obtained using a water-softening system that can cause harm to your plants. 

So, ensure you use the water softened by your water softener on your plants only occasionally or adopt the alternative watering methods stated in this article.