When the warm weather hits, you may spend countless hours laying outside by the pool, but have you ever wondered why the color of your pool water is blue, while the water in your glass is clear? Rumor has it that this is because your pool water is reflecting the blue sky, even on a cloudy day. However, this makes it not necessarily true.
Why Blue?
What really gives your pool that blue color is the quality of the light and how it will interact with the water molecules. Similar to the way a sunset works, water can easily absorb the red parts of the light spectrum. While the blue parts take more time to work its way through the water. What you see is those colors working its way through.
For the most part, the deeper the water is in your pool, the more dark of a blue it will appear. Here is why:
- Sunlight is white, which is made up of all the colours of the spectrum.
- The molecules in pool water absorb light from the red end of the spectrum when sunlight falls on the water.
- By removing the red, the light which ends up being reflected has a slightly blue hue which can vary in richness by water depth.
Green, Brown, And Everything Else
Sometimes you will see other colors reflected in your pool water. If you see green or brown, this could indicate algae and may be a sign it is time to clean your pool. You may also see other colors due to the color of the tiles or paint in your pool. This may be a fun factor to consider when deciding how to decorate your pool.
One way to help maintain that pretty blue color is by always maintaining the right balance of chemicals for your pool. This will kill off algae causing bacteria and prevent growth.
Test The Color
If you are interested in learning more about how pool water and color are related, try this fun experiment. Take a white bucket and submerge it in the water. Towards the surface, the bucket will appear to be a light shade of blue. As you submerge the bucket deeper, towards the bottom of the pool, you will notice the color begins to grow darker. This is because less light is reaching the bottom of the pool, thus less light is moving through the molecules of the water.
Just like swimming in your pool, science is fun and it is all around us! Understanding why your pool water is blue does not only help you understand the world around you a little bit better but can actually help you take care of your pool! Keep your water clean, balanced, and blue!