Why Does My Pool Look Green But The Water Is Clear?

Why Does My Pool Look Green But The Water Is Clear?

Algae is one of the major factors that tends to influence coloration in our pool. Algae bloom is often prominent in pools with low chlorine levels and sometimes heavy rainfall or poor circulation in the pool also contributes to algae in our pool if algaecide or proper treatment is not implemented.

Sometimes, your pool may be algae free or high in chlorine but still green, and you begin to contemplate the common cause of this discomforting sight. There are a few possible reasons for that, for instance, when not shocked properly.

Shock goes beyond simply filling the pool with chlorine and leaving. You have to keep going until the chlorine outpaces the organics and can sustain its lead. Therefore, perform it once every hour.

Chlorine is eaten by the sun and biological matter. It is therefore ideal to add it right before dusk (exactly as you did before bed), as it will work better (last longer and work longer before it degrades due to sunlight) and clear organics (leaves, etc.) out of the pool, so chlorine may cleanse the water without interacting with them.

A chlorine-resistant algae, pollen, or, most commonly, an excessively high pH level can also cause clear pool water with a green tint. A pool’s pH can rise above 7.8, at which point even high chlorine concentrations become ineffective at sanitizing the water. Additionally, metals in the water and pool’s components can oxidize, turning the water a greenish color.

Not brushing may also cause the green coloration in our pool. In a pool with algae, the walls, steps, floors, light niches, etc. may get covered with algae growth. It can be temporarily bleached by shock, making you think it has vanished, but unless you continually brush the surfaces, it will come back.

Can too much chlorine make your pool green?

Having low free chlorine in the pool leads to algae bloom and green coloration in our pool, which leads to discomfort. Be careful of adding too much chlorine to your water because it may also give you a disconcerting sight as your pool water may turn green.

Adding too much chlorine to pool water can cause those metals to oxidize and turn the pool a different shade of green. Chlorine can oxidize metals like manganese, copper, silver, and iron in the pool water . This is more likely to happen with copper. If you have ever noticed an ancient statue made of copper, you will know that with time, copper tends to oxidize and take on a blueish green hue.

A similar phenomenon occurs when metals in your swimming pool’s water are oxidized by chlorine; they turn greener, which causes the coloring.

The brightness or cloudiness of the water is the primary distinction between light green water caused by metals oxidizing and light green water caused by algae.

Algae-covered water always has a slight foggy or murky appearance. Your pool’s sides may even start to grow some algae, which is a surefire sign that you have an algae problem.

In contrast, water containing oxidized metals will occasionally seem bright in pictures to the point of luminescence. There won’t be any algae growing on the sides, and the water probably won’t appear too cloudy, despite the hue varying from a very brilliant green to khaki or dark apple green.

What happens if you put too much shock in a pool?

The phrase “everything in moderation” has probably crossed your mind at least once. Surprisingly, this generalization can be safely disregarded when shocking your pool. The short answer to the question “Can you over shock a pool?” is generally no. However, you can employ either more or less shock than is necessary.

A swimming pool cannot be over-shocked or over-filled. Algae will be killed off in your swimming pool if you add too much shock or shock it too much. The chemical equilibrium of your pool will be thrown off if you apply too much shock.

Whether or not you over shock the pool, it’s likely to happen that way. Depending on the product you use, the pH will either increase or decrease. Additionally, you won’t be able to utilize the pool for a few days.

Owners of vinyl-lined pools should be aware that they should avoid letting too many shock granules settle on the bottom liner. Pool shock, which contains a high concentration of chlorine, could permanently harm the pool and cause leaks.

The short-term effects of too much shock on a pool are typically unproblematic. Chlorine levels in pools will increase significantly when shock is added. The effectiveness of the chlorine will be diminished if the pH is off. When the chlorine levels drop again, this may cause algae issues.

What happens if there is not enough chlorine in a pool?

The primary purpose of putting chlorine in water is to kill germs. In your pool, chlorine when applied produces a weak acid called hypochlorous acid, which destroys bacteria like salmonella and also some viruses that cause diarrhea and swimmers’ ear. Chlorine is frequently used in swimming pools, including saltwater pools, for four specific reasons:

  1. It oxidizes, which improves the clarity and sanitization of the water;
  2. It kills algae and stops it from spreading throughout a pool.
  3. It stabilizes pool water and creates water quality that is pretty consistent.
  4. It sanitizes and kills bacteria.

According to statistics, swimming in a pool without chlorine increases your risk of getting sick since you could come into contact with contaminants that chlorine cannot remove. Keep in mind that because of your skin’s permeable nature, small pollutants can enter.

Unchlorinated swimming pools resemble large puddles of muddy water, and the pool wouldn’t be all that visually pleasing due to unchecked algae development. Fair enough, swimming in a pool without chlorine definitely wouldn’t harm you, but the hazards to your health and safety would be substantially higher.

What’s the difference between pool shock and chlorine?

Chlorine and shock are not the same thing; they are entirely different, although there are relativities.

A pool has nothing to do with electricity or with unveiling anything wholly unexpected, however alarming it may sound. The act of shocking involves introducing chemicals to your pool, often chlorine, to break up chloramines, commonly referred to as mixed chlorine.

Immediately increase the chlorine level. Chlorine is well-known for its disinfectant properties, particularly its ability to effectively clean swimming pools by eradicating bacteria.

The key distinction between shock and chlorine is that shock is a concentrated chlorine solution whose sole purpose is to shock by boosting the chlorine level in the pool. Chlorine, on the other hand, is a universal sanitizer that is used to keep swimming pools clear and sparkling. Others include;


The shock is available as a liquid or a powder, both of which contain 12.5% sodium hypochlorite, increasing the chlorine level to 5–10 ppm.

Shock is used in swimming pools and other bodies of water to purify, speed up the level of free chlorine that sanitizes the water, eliminate all germs, and present water that is clear and sparkling.

Shocking water causes a reaction of disinfection active chemicals, removes free chlorine, and raises the chlorine level to 5 ppm or higher.


For the purpose of destroying microorganisms, chlorine creates hydrogen and hydrochloride ions that are later dissociated in the water. PVC and microorganisms in water bodies are both destroyed by chlorination.

A little concentration of chlorine combined with an acidic reaction helps to kill germs by breaking the bonds of disease-causing bacteria. Chlorine is an effective halogen.

Does high pH turn a pool green?

High pH is one of the most common problems encountered by pool owners. pH is a measure of the acidity or alkalinity of the water or pool. If the pH isn’t properly balanced, then it may lead to certain problems for the pool and its users.

A high pH in the water can also result in hazy water, skin rashes, and scaling on pool equipment. Scaling inside pipes may accumulate over time, reducing water flow and taxing your pool‘s circulation system, which may require expensive repairs.

The water becomes overly alkaline when the pH rises above 7.8. Chlorine is the pool chemical that eliminates microorganisms, hence leading to algae buildup and causing green coloration in the water.

A prompt response can save you some trouble if your pool begins to test for a high pH. Setting up a suitable chemical balance should start with adjusting the alkalinity of the pool water. Remember that managing an alkaline environment becomes more challenging the higher the alkalinity.

Does high alkalinity cause green water?

The presence of algae is certainly the major cause of green coloration in a pool. Algae can just exist and survive in our pool. Hence, their existence in the pool is influenced by our activities in the pool and favorable conditions in the pool chemistry.

You have algae because of an imbalance in pH or alkalinity (while there is adequate chlorine). Chlorine’s efficiency is considerably reduced by pH values that are either extremely high or extremely low.

The effects of the chlorine you use to keep algae under control may be diminished by excessive alkalinity, which can also cause green water for different reasons. And although irregular pH is caused by low alkalinity, high alkalinity often results in levels of pH that are obstinately high and challenging to decrease.

Aside from turning pool water green, high alkalinity has an effect on the pool users too, as it may lead to itchiness and burning eyes. Total alkalinity should be between 80 ppm and 120 ppm.

Is it safe to swim in light green pool water?

Whereas the green algae in the pool is not entirely harmful to health, the bacteria that feeds on this algae can result in health issues for the pool users. If there isn’t enough chlorine in your pool, there is a possibility of algae bloom, and even the mildest case of algae bacteria can lead to infection.

Swimming in green water tends to expose you to bacteria-hosting algae. Your skin may become infected while swimming in green water, and consuming pool water that contains algae may make you sick. In addition, algae can be quite slick, which can lead to slips and falls.

Moreover, the presence of algae in a pool increases the risk of drowning as there is less visibility in the pool and you won’t be able to see if someone needs help.

How long does it take for a green pool to clear after shock?

After shocking your pool, there are certain principles that should be implemented so as to obtain clear water in your pool.

The pool needs to be filtered for a long enough period of time each day to cope with any algae or debris. Therefore, you must set your timer when the shocking procedure is over and everything is back to normal.

The amount of time the circulation system needs to circulate the total volume of pool water (in gallons) through the filtration system is known as the turnover rate, which determines how long the pump should run.

Will a clarifier clear a green pool?

Once the algae has been properly removed from your pool, you may clear it out by observing a change in the color of the water.

However, if you observe that your water is still green, after super chlorinating your pool and adding an oxidizer, you can now apply your pool clarifier and allow it to circulate for 12 hours, as this process helps to group the algae into vacuumable chunks. Turn off your pump and wait for the cloudiness to clear.

Note that in the case of particular foggy pools, this could take days .

Why did my pool turn green overnight?

Algae growth in the water is the primary cause of the greening of swimming pool water. You might be surprised by algae growth overnight during the warmer months because of how quickly it can grow, especially in warm weather. A chlorine imbalance or deficiency in the water is typically to blame for this.

Because chlorine is a powerful sanitizer, allowing it to fall even for a single day can result in an algae bloom. Therefore, it is a general necessity to check your chlorine level in your pool in order to avoid unpleasant surprises.

Regardless, follow these five easy procedures to restore your pool’s health without draining it.

The following steps only apply to chlorine-based sanitizer-based pools.

  • pH balancing and chlorine shock your pool water.
  • Inspect and repair any problems or malfunctions in your filtration system.
  • Thoroughly brush your pool’s walls to dislodge algae and properly rake up dirt chunks from the bottom of the pool floor.
  • Ensure you backwash your filter.
  • Return your filter valve and run your pump.

If you notice a dark green in your pool and your pool‘s bottom is not visible, you may use a clarifier or flocculant the next day to take out dead algae.

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