Why Is My Pool Green?

The worst part of being a pool owner is how quickly your pool can get filthy if you don’t maintain it. If you take care of your pool correctly, you should have no worries about your pool turning green, because it most likely won’t. However, sometimes life gets busy, and it can be easy to forget about the smaller responsibilities, like taking care of a pool, because it is not always as important as taking care of your family and your house.

For whatever reason that your pool turned green, the only thing you can do now is to take steps towards clearing it and then take preventative measures in the future. It may take a few days for the pool water to clear itself, depending on how green it is.

So, what is the reason for a pool turning green? It could be one of a few reasons, but the most common and likely scenario is that there is an overgrowth of algae in your pool.

What Is Algae and Is It Harmful?

Algae look like they are plants because of the dark green color and the way they can create a moss-like foam on the surface of your pool water, but it is an animal. They are called protists, which means they are living creatures, but are so incredibly tiny that you see them with just your eyesight. The definition of algae is a group of predominantly aquatic photosynthetic organisms.

Small amounts of algae are always in your pool, but they remain stable and unharmful as long as you maintain the balance of alkalinity and chlorine levels. It is not hard to keep the levels of pH and chlorine balanced, but it can be thrown off easily if you don’t take care of the water for several days.

The real problem occurs when the algae are overgrown and start attracting harmful bacteria and other insects to live in the pool. Some bacteria enjoy eating the algae, so they make a home in your pool, which causes the water to be unsafe for swimming.

How to Prevent Your Pool Water from Turning Green

There are three main steps you can take to prevent your pool from ever turning green in the first place. Remember that you must keep up with these steps and do them at least a few times a week, every week.

1. Clean the pool filter

On the side of your pool, there should be a pump that pulls water inside of it, runs it through a filter and back out into the pool. It keeps the chlorine circulating and clears out small debris that is floating in the water. This pump only needs to run about two hours each day, which you can set on an automatic timer. However, the pump won’t run sufficiently if the filter is dirty.

To clean the filter, close off the hoses that connect it to the pool, pull out the filter, and rinse it thoroughly with a hose. The filter is easiest to clean when it is still soaked with chlorine water; if it’s dried out, try soaking the filter in a bucket of pool water or chlorinated water before rinsing it.

2. Clear Debris Often

No matter what you do, leaves, dirt, and debris will always find its way into your pool. The water pump pulls out most of the smallest particles that float in the water, but the larger pieces, like leaves and dead bugs, will remain until you scoop them out with a net, otherwise known as a skimmer.

You can find a skimmer at your local pool supply store or online. It doesn’t matter what type of net you use since they are pretty much all the same, but if you have a bigger pool, you will want a pole for the skimmer that is extra long.

Swimline Heavy Duty Leaf Skimmer

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U.S. Pool Supply Professional 12-Foot Blue Anodized Aluminum Telescopic Swimming Pool Pole

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3. Test the Chlorine and pH Levels

To be able to maintain and adjust the chlorine and pH levels in your pool, you have to test the water first using a pool test kit. A basic test kit comes with a clear test block to hold pool water for comparing against the scale labeled on the side, and two dropper bottles; a red dropper bottle for pH testing and a yellow bottle for chlorine testing. Follow the instructions in the kit to conduct the tests as accurate as possible.

Once you test both the chlorine and pH, if either of the results tells you that the levels need to be adjusted, you can make changes accordingly. To raise the chlorine, you will need chlorine tablets, and to raise or lower the pH you can use either a pH Up or a pH Down solution.

U.S. Pool Supply Standard 3-Way Swimming Pool & Spa Test Kit

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Clorox Pool&Spa Active99 3″ Chlorinating Tablets

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Clorox Pool&Spa pH Up

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Pool & Spa pH Reducer

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No More Green Pool!

Follow those three steps of pool maintenance and your pool should stay nice and clear all year round, but if it does turn green (or if it already has), use a pool shock solution to turn the water back from green to clear. As soon as you notice that your pool is green, don’t wait to clean it. The first thing you should do is to buy a shock solution. After that, clean or replace the pool filter, and then vacuum the pool if possible.

If you have already tried everything with not much luck, the workers at a pool store can help a lot with cleaning pools. They usually allow you to bring some of your pool water into the store for them to conduct further tests, and then they can give you their professional opinion and recommendation on what steps to take to remove the green color from your pool.

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