Will pool water kill grass is something you might want to find out if you have a major pool drainage coming up. We understand that you might want to recycle the pool water and give it to your lawn instead.

Pool Water is Not Safe for Grass

Let’s take a deeper look at how chlorine, bromine, algaecides, and salt present within the water in the pool affect the grass.

This article also contains our favorite method of draining a pool without harming the surrounding lawn grass.

Will Pool Water Kill Grass?

Yes, pool water will grass because it contains a chlorine and also other chemicals added to pool water to keep it clean, such as bromine and algaecides, these would kill grass when in contact. If you have a saltwater pool, then even this salt will dehydrate and kill the grass. 

– Chlorine Water

It is key to know that pool water contains chlorine, as it is the cleaning agent of it. Chlorine in more than 0.1 parts per million water is toxic for grass and plants. This chemical is one of the best antiseptics to clean pool water of microbes. Therefore, it is no wonder that it kills grass permanently.

Using Chlorine on Pool Water

It disturbs the soil’s pH level, making grass and nitrogen-producing bacteria difficult to survive. It also gets absorbed into the grass blades via roots, making them brittle and dry as a result.

Chlorine toxicity leads to a rapid dissolution of minerals and nutrients from the soil. This will lead the grass to be weak and not able to repair itself from chlorine damage without access to water and nutrients. 

– Algaecides

Chlorinated pool water must also continually add algaecide to keep it free from turning green and slimy, even if it is left for a short period, however, when this water with this chemical is used for irrigation purposes, the soil of the grass will be weakened.

Algaecides with copper in them might cause stunted growth in all plants growing in the lawn, and this would harm the growth and spread of the grass, as they are also majorly affected through the irrigation, despite excellent lawn care. The green color of the grass fades and becomes lackluster in appearance.

In addition, some algaecides may even contain bleach or added chlorine among their ingredients list. These are more dangerous and will kill grass, especially if it is recently added to the pool, as the chemicals are at their active process.

– Salt Water

Saltwater pools are not healthy for your grass at all, simply because the salt agent dehydrates the grass. Those who live near the sea in coastal areas will understand when we say that grass would not take kindly to saline water. If you have no option but to use salt water in your home pool, then try to protect your grass from this water.

The grass might tolerate occasional spillovers of salty water onto the lawn. You might notice that grass in the immediate periphery of the pool often turns yellow because of constant spillovers. When you drain this pool, try to direct the water away from the lawn during it. Use a long hose to drain salt water towards the driveway instead. 

Fish in the Salt Water

The salt that comes from saline water is deposited into the soil and causes long-term damage. Grassroots become dehydrated because water is drawn out of them. This is compounded by sodium and chlorine toxicity as salt breaks down.

Grass from salt toxicity becomes dry first and then turns yellow or brown. It is clear to see when the grass is dry because the blades do not straighten up when folded and easily break down.

– Bromine

Most pool water have the element bromine added to it for hygiene purposes, and if you add bromine to the pool, and then irrigate the grass with this water, then such water will kill lawn grass, especially if splashed on the water in a large amount.

Bromine seeps deep into the soil through water and attacks the roots directly, and when the root is hurt, the nutrients won’t pass smoothly to the grass as a result, the grass might end up dying permanently in patches. 

Checking Bromine on Pool Water

Unlike chlorine, bromine does not evaporate from water over time or due to high temperature or sun exposure, it stays abundant as you have placed it. Such water will have to be properly treated chemically just to be drained near plants or vegetation.

Many people prefer using bromine instead of chlorine to keep pools sanitized. Bromine is just as good at killing bacteria in water as chlorine, if not better. Unlike chlorine, it is more stable and does not evaporate in hot temperatures.

This makes it the choice of sanitizer for pool owners in hotter regions during summertime. Add bromine instead of chlorine in warm water to keep swimming in winter. Bromine is an excellent oxidizer and algae-killer that protects the water from harmful free radicals and microbes.


How To Use Pool Water in Safe Way for Grass Irrigation?

You can use pool water in a safe way for grass irrigation by reducing the chlorine amount before draining it. In order to drain it safely, you must pump the drainage well to avoid clogging, and lastly, to remove the chemicals you must dilute the excess chemicals.

– Reduce Chlorine Before Drainage

So you have decided to drain your swimming pool and think it is a huge waste of water just to let all that water go?

You can decrease chlorine levels in the water so that at least salt-tolerant plants and grass can be watered with it. Even if you decide to use this water for something else, you should still decrease its chlorine content to stay safe.

You must stop adding more chlorine if your pool water has only a little more chlorine than normal levels usually deemed safe.

Chlorine is a volatile compound that tends to evaporate over time. Use the pool, swim in it, and keep the water exposed to air to reduce its chlorine levels as quickly as possible.

Many like to keep their pools covered during the daytime because swimming in water is not good for the skin. However, exposing pool water to bright sunlight makes chlorine dissipate faster than ever.

Reducing Chlorine Before Pool Drainage

Remember that you must turn off the pool’s chlorine feeder and uncover it, and basically only two hours of direct exposure will reduce chlorine levels by as much as 90 percent because it is an evaporative chemical. 

In addition, the heat of the sun or heat being exposed would also work to remove chlorine rapidly from water in the pool. It helps if you have an electrically heated pool, things get quite easy for you. Heat the water temperature in the pool to 100 degrees Fahrenheit, or more than the recommended levels. 

You can add hydrogen peroxide to the pool in a calculated amount according to the quantity of water in it. However, the use of hydrogen peroxide, is specifically meant for cleaning the water in the pool, because it only works when the water is alkaline, so you might have to adjust the pH in the water before using it.

Chlorine-neutralizing products are available in the market that can decrease it without affecting the pH or hardness levels of the water. Nonetheless, you can use these products in the amount recommended by the manufacturer just before emptying the pool.

– Safely Draining Pool Water

Now that we have established that swimming pool water is not good for the grass, it is time to see how you can drain it without spilling it on the lawn. There is more than one way of emptying a pool, but we advocate using the submersible pump, as it will save you a lot of time.

First, you must note that for an average-sized pool present in most US houses, a submersible pump draining 700 gallons of water per hour works the best, and take things into consideration using this knowledge.

This would cost you about 50 to 100 dollars each, depending on the type you choose to buy. Better yet, borrow this pump from a hardware store because you rarely get to use it.

Clean your pool first of all solid debris using a pool skimmer. Otherwise, it will clog up the hose and the pump and slow down your drainage.

Safely Draining Water in Pool

You may even invest in a premium quality draining hose of the right diameter to attach to the pump. Attach one end securely to the pump and away from the lawn. Then lay the hose on the ground as straight and flat as possible

The submersible pump needs to be submerged completely inside the water within swimming pools. Make sure its waterproof power cable is directly attached to an outlet. Please only use an extension cord and place it near the pool.

Now, you must turn the pump on and start draining the water out. You will have to get the pump out of the water while it is still submerged, leaving water in the pool. The last few gallons of water can just be removed using a vacuum pump.

If the hose of the subversive pump is placed well away from your lawn, then there is no risk of lawn flooding from chlorinated pool water, to make it safe for irrigation process of the grass. 

– Dilute Accidental Spillovers

Some accidental spillovers are inevitable when you own a pool built near the near. The easiest solution to deal with this, is to dilute and dilute the affected area and then to use that water.

Whether it is salt water, chlorine, or bromine, you can reduce its impact on the soil and grass by using a large volume of fresh water to double-wash the patch where the spillover occurred, and with the removed chlorine from the pool as you drain it, you can reuse the water safely just as you hav diluted it. 

Accidental Spillovers Near Pool

Sometimes the spillover is not so noticeable, and the grass might die in patches. In that case, pull out the dead patches and reseed that area. If the pH of the soil has been disturbed, then soil amendments will help bring them to be normal.

Overall, now you are safe to use the pool water, where the chemicals are sorted out, diluted, and drained. This water, that you will be using for irrigation is no longer toxic with chemicals as the pool water it, on the contrary, they are drained and you can safely use it. 


Now, you know how chlorinated water pool will be harmful to your grass.

Since we are at the end of our article, a brief recapitulation is necessary.

  • Pool water used untreated and in an undiluted form will kill the grass.
  • Chlorine of more than 0.1 parts per million in water will permanently kill grass and destroy grassroots and grass blades. 
  • Even if you substitute bromine for chlorine as an antiseptic pool alternative, that is still harmful to the grass.
  • Be especially careful when using salt water in the pool because most grass varieties cannot tolerate salty water and die.

Here in this article, you learned reasons why and the process of how pool water could harm your grass’s health. It is foolish to pour drained water into the lawn and expect it to become lush and healthy, of course you can use it as you dilute it first.

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