Pool water is also known as chlorinated water (greywater). Besides chlorine, pool water contains many other chemicals like bromine, cyanuric acid, oxidizers.
Pool water cannot be used to water plants unless the chlorine content is reduced. Chlorine eliminates bacteria and algae in pool water by disinfecting or killing action. It also oxidizes other materials such as dirt and chloramines and can harm plants in high quantities.
In this article, I will share relevant information regarding the effect of chlorine on plants and what you can do if you consider watering your plants with pool water.
Can Pool Water Affect The Plant?
Pool water can directly affect plants’ normal growth and functioning. The chemical known as chlorine is present in pool water which is highly dangerous for plants in higher quantities.
Chlorine is first converted into chloride in soil. It is then taken up by roots to the entire body of plants. Pool water is often highly chlorinated, which raises chlorine levels even more.
It is acceptable to water the plant with pool water if a minute amount of chlorine is present. However, if the chlorine level is higher in the pool water, think twice before watering the plant with it.
The high content of chlorine can cause the death of your plant.
For example, a high level of chlorine in water turns the leaves of plants brown or yellow entirely or just targets the edges.
Furthermore, plants will begin to shed their leaves more than usual if watered with pool watering containing high amounts of chlorine.
There are 10.4 million residential and 309,000 public swimming pools in the United States, according to the Association of Pool & Spa Professionals (APSP).
Effects of Chlorine on Plants:
Chlorine is used in pool water as a disinfectant of pathogens.
Chlorine has a vast effect on plants. If presented in smaller quantities, it may prove beneficial to plants by killing harmful pests and bacteria.
However, if present in high amounts, chlorine can dramatically damage the overall health of plants.
The negative or positive effects of chlorine depends on the chlorine concentrations and the type of plant watered by such water.
If chlorine concentration is below 100 ppm, it will cause the following problems:
● It can cause leaf burn, which reduces excessive foliar absorption or diminish root uptake to stop plant growth.
● Too much chlorine can accumulate in the tissues of plant leaves, which will result in burned or scorched appearance.
● The plant which is being watered by excess chlorine water may have small leaves.
● An extremely high amount of chlorine can cause toxicity in plants. If your plant has brown or dead tissues at tips, between the vein, or at margins, your plant is slowly dying.
● Too much chlorine can injure plant roots as well.
A high level of chlorine is poisonous for plants. Watering a plant with such high-level chlorine can give you devastating results.
How To Reduce The Effects of Chlorine in Soil?
Reducing chlorine is not a hard job. You can simply reduce the level of chlorine by treating the water with gypsum.
50 lbs. per foot is required of gypsum in a loamy soil.
However, less gypsum is required in sandy soil, which can be thoroughly watered to leach out toxic levels of chlorine.
Can Pool Water Affect Grass?
Pool water will not have any major effect on grass as the chlorine content is not enough to cause a disruption in the nutrient uptake.
Additionally, lawn grass are often exposed to full sunlight and apart from being very rugged, the sunlight reduces the effect of chlorine, which is a free radical.
A free radical is an uncharged molecule (typically highly reactive and short-lived) having an unpaired valency electron.
When exposed to sunlight it takes as little as two hours of sun exposure to reduce chlorine content by 90%.
However, because the sun’s UV rays break it down, the chlorine turns into a gas. This gas then rises into the air instead of mixing with soil or burning the leaves of the grass or plants.
How To Remove Chlorine From Pool Water?
There are three methods to remove chlorine from pool water. The methods are listed below.
- By evaporation
- By chemical neutralization
- By filtration
It’s a slow and easy process but proves to be beneficial for dispersing chlorine. Because chlorine is highly volatile and can quickly evaporate without creating any hindrance, this process is a little time taking.
However, another benefit of this method is that it is free of cost. There is no need to spend a penny.
Just simply leave the water to stand under sunlight, and the chlorine will automatically evaporate.
By Chemical Neutralization:
This method involves adding more chemicals to take off the chlorine. The chemical which is excessively used to neutralize pool water is potassium metabisulfite in the form of tablets.
Simply add the tablet to chlorine water. After dissolving, it will automatically neutralize the chlorine.
A single tablet proves to be beneficial to clean 20 gallons of water. This process is fast and is also pocket-friendly.
In this method, a process called reverse osmosis is used. Reverse osmosis uses a semi-permeable membrane to filter the water to make it free from impurities.
This is a quick process, yet one disadvantage is present.
It is a costly process, and the system should be installed at your place to enjoy the facility.
This method of purifying water from impurities is commonly used on a large scale, especially in factories.
Water From Saltwater Pools:
According to sources, watering plants with salt water is beneficial for some plants like yaupon, wax myrtle, viburnum.
The pool that contains saltwater has an average salt content of about 2500 – 4000 parts per million.
Is Pool Water Safe for Plants?
Different plants have different capacities for bearing things. For example, it is safe for plants when salt is provided on leaves and stems from the top.
Pick a small patch of your plant (one that is fine to you) and water it with saltwater. And wait for a day or two for results.
If the result is in your favor, it is proved that saltwater is safe for your plants. If not, simply avoid watering saltwater to plants.
The highly salt tolerable plant can tolerate up to 18g/l saturation extract. Moderately tolerable plants can bear saltwater up to 5g/l, and the sensitive groups can take almost 2.5g/l of saturation extract.
How Will The Salt Affect The Plant?
If salt is absorbed by plants through the soil, it may accumulate, resulting in dehydration of plants.
We all know that plants absorb water through roots through the process of osmosis.
Osmosis is the process by which solvent molecules move through a flexible membrane from a region of high water to low region water.
The salt present in the soil is absorbed by plants, where it pulls away water from cells, resulting in cell dehydration.
Remember, excess of anything, be it even the amount of salt in plants, can be dangerous.
A high amount of salt can cause “salt stress” in your plants, causing growth inhibition and even death during prolonged subjection.
Growth inhibition is a similar reaction to plants when watered with Well water where there may be many salts present.
How To Remove The Salt From The Plant?
Leaching can be an effective method of removing salt content from the soil. In this process, you add salt-free water to the soil to dissolve the unwanted salts.
The water should be added via top watering and not through the bottom watering method.
Furthermore, it also aids in lowering the level of salt below the root area.
Plants That Are Tolerable To Chlorine:
All plants require a small amount of chlorine to grow, but too much can harm or kill some.
Chlorine can accumulate in leaf tissue, resulting in leaves with a scorched or burned appearance.
Plants with scorched leaves have brown or dead tissue on the tips, margins, or between the leaf’s veins.
However, there are some plants that can handle a chlorine shock when they are watered with pool water.
Here is a list of chlorine-tolerant plants.
- Palm trees
- Vines include –
- Deep green ivy
- Creeping Rosemary
- Climbing fig,
- Shrubs including –
- century plants,
- Indian hawthorn
- Grasses include –
- pampas grass
- maiden grass
- sea oats
Are There Any Nutrients in Pool Water?
Plants need different nutrients for proper growth and functioning. However, some are required in small quantities and some in large.
The nutrients which are necessary in small amounts are called micronutrients. And chlorine is a vital micronutrient for almost all plants.
According to Iowa State University Extension and Outreach, Pool water also contains nutrients like zinc, bromine.
If chlorine toxicity is less in water, then these nutrients can prove helpful for plants.
|Mineral||Uses in Plants|
|Zinc||Helps plants produce chlorophyll|
|Bromine||Plays an essential part in photosynthesis|
Pool Water With Algae. Is It Ok For Plants?
According to scientific research, algae do not directly harm plants. The algae which are present in pool water will also not directly damage the plant.
However, it can slow down the process of gas exchange between plants and the environment. Thus, damaging the plants indirectly.
The algae, over time, can build up, causing unforeseen problems.
Algae formation on pots and plug trays absorbs nutrients meant for plants and creates a barrier making it difficult for water to penetrate to the root zone. This will affect the quality and the aesthetics of plants.
Can you Use Pool Water to Water Lawn Grass
Pool water can be used in small quantities to water grass. Grass plants are often very robust, selectively filtering out the harmful chlorine from the pool water.
Chlorine is a free radical and is usually deemed useless when subjected to sunlight.
As a result, chlorinated pool water should be allowed to sit in the sun for a while before it is applied to lawn grass.
How to Water Plants With Pool water
Misting with Pool Water
- Any household spray bottle can be used as long as it is cleaned properly.
- The water should be filtered and clean for the spray bottle to expel the water without clogging
- Add the pool water to the spray bottle
- Spray or mist the plant on the top as well as the underside of the leaves
- Also, spray the topsoil with water.
Misting with pool water should be done during the morning periods or late evenings to allow the plant to absorb moisture and nutrients.
This also prevents the heat of the day from drying out the moisture too quickly.
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Bottom Watering with Pool Water
Bottom watering will allow for the pool water to be absorbed thoroughly into the soil without having it in an overwatered state.
In doing so, the total mass of the plant roots will be able to access the nutrients provided by the water.
Bottom watering is an effective method of watering plants that ensures the entire root structure gets water without the risk of overwatering your plants. See the bottom watering plants article here.
How to Bottom Water Plants with Pool water
- Use a small, flat container two inches larger than the plant pot
- Place the plant into the container
- Add the pool water so that the water level reaches 1 to 1 ½ inches high on the side of the plant pot
- Allow the plant to sit in the water for 15 to 20 minutes
- After the time has passed stick your finger in and test the soil for moisture
- Once you feel that the soil is moist (not wet) you can remove the plant.
- Place the plant to drain out any excess water
See our helpful article on how to apply fertilizer when bottom watering which will give helpful insights on how to properly add nutrients to plants when bottom watering.
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To conclude the above discussion, pool water can be used on plants after altering its chlorine content.
A lower amount of chlorine will not harm your plants. However, higher content of chlorine in pool water can dramatically damage your plant.
You can use different methods to reduce the chlorine content from your pool water if you want to water your plants with it.