Is it Safe to Swim in a Green Swimming Pool?

green algae

Swimming pool water that is green is an indication of algae in the water.

So, is it safe to swim in green water? No, the pool is probably not dangerous to swim in but it would be smart to avoid swimming in green water. If you decide to swim, you should be aware of any new irritations or rashes and get out of the pool immediately if you notice any signs of any.

Causes of Green Pool Water

There are five main causes of green pool water:

1. Lack of Chlorine

Your pool water will quickly start to grow algae and turn to a green pool water if your pool does not have any chlorine. If your swimming pool water is green, you should keep in mind that can attract mosquitoes and other insects. If you are doing your regular maintenance and you notice low or lack of chlorine, it would be a great idea to do a pool cleaning and then add more chlorine until it has reached it’s optimal levels.

2. Oxidized Metals

Oxidized metals, usually copper will turn your pool water green. The metals usually from through cheap algaecides, acidic water or from metal components corroding from your pool equipment. Shocking your swimming pool will easily oxidize these metals, and if they are present in large amounts they will turn the pool water green. You do not want to leave your pool water green otherwise it can stain your pool’s finish and even turn a swimmer’s hair green.

3. Excessive Pollen

Airborne pollen is quite hard for the filter to remove them. As airborne pollen builds up in your pool and settle, they give the water a yellow or green look. A green pool due to pool doesn’t cause any harm, despite it’s unpleasant look.

4. pH is Too High

pH is a measure of how acidic or basic the water is. There can be several factors that can cause a high pH level in a swimming pool. Anything can cause the pH level to be high that comes in contact with your pool water. One of the ways that chlorine because ineffective is due to a high pH level.

5. Not Running The Pool Pump Enough

The pool water needs to be circulated to keep it filtered and clean. The circulation also helps spread the chemicals you add to the pool water. So now you are wondering for how long? Well the typical time is one hour for every ten degrees it is outside. If it’s 90 degrees out, the pool pump will need to be running for at least nine hours a day.


It will be a good idea to regularly test your pool to avoid having a green pool. If you notice any signs of algae, it would be a good idea to give it a pool cleaning. If you must swim in a green pool, I would highly recommend to keep your head above the water at all times, and to take a shower right after you swim. 

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