Maintenance How does swimming pool water turn green and exactly what are the consequences of swimming in a green pool? Well there are many but first lets go over why your pool is green in the first place. The green you see in your pool is what as known as Algae. While generally Algae is harmless in a river, in a pool it is a different story. In a pool its either dark or light green and cloudy. We will explain why below. Contents1 Why Does My Pool Turn Green?2 The Lack Of Free Chlorine Matters!3 Why Can I Swim In A Lake But Not A Pool?4 So The Verdict? Is It Safe? Why Does My Pool Turn Green? While there any many reasons why your pool would turn green, most of the time it is due to your pool pump not working and filtering the water. There have been many stories of people going on holiday and their pumps dying, and then people come to fix the pump without turning it back on. We have also heard pools turning green after rain but we think that might be because water is running off into the pool. Another issue is your Levels may be incorrect or may need adjusting. If this has happened to you, the best thing to do is to “shock” the water with bleach and then vacuum up all the remaining dirt, pollen, leaves etc. You want to get rid of all algae. Normally shocking a pool can take 7 days but it is best to check your Levels to be sure when it is safe. Sometimes people ask why did my pool turn green after i shocked it? Well thats generally either incorrect shocking or using the wrong products! We suggest using CLOROX Pool & Spa Green Algae Eliminator (NOT BAKING SODA!) to shock the pool correctly! The Lack Of Free Chlorine Matters! When your pool has lots of algae, your FC (free chlorine) level is nearly 0. Without any FC, generally speaking a pool is unsafe to swim in. Its not exactly the algae that causes the danger in the water, its actually the other things that end up in the water. Chlorine is what keeps the pool sparkling clean. The algae will be essentially eating the chlorine. Without FC, and with all that algae, what ends up happening is certain bacteria have the potential to thrive. If you didn’t know, various animals will come and swim, drink and also nard in the water. So while you might not mind the Algae, you may mind the fresh duck fecal matter that has been sitting on top of the water for the past week! While you are not guarantied to get sick from swimming in a pool with algae, it really isn’t a good idea. I mean you wouldn’t swim in a swap would you? Why Can I Swim In A Lake But Not A Pool? Lakes and rivers do get algae, but they are more of an self sustaining ecosystem. Lake will have a fine balance of bacteria, much greater water volumes, and filtration going on by the plant life. There are issues with bacteria in lakes too, many beaches will shut down on really hot days if the bacteria takes off, it’s just much more likely to happen in the small space of a pool. This is why it is advised you don’t put your head underwater when swimming in lakes. With a green pool, you end up with a much higher chance of getting an illness (especially a throat, eye or ear infection). So The Verdict? Is It Safe? Well, in the end its up to you. But I wouldn’t put the safety of my children or family in harms way because I forgot to clean the pool. As said before this is NOT the same as swimming in a river or lake as they are a natural ecosystem and it doesn’t matter if they are green (Most of the time). So how to get your pool blue? Remember if its GREEN, We suggest using CLOROX Pool & Spa Green Algae Eliminator to shock the pool correctly!! If you think otherwise we would love to hear from you in the comments below!