Low Chlorine in Pool – Safe to Swim In or Not?

Low Chlorine in Pool - Safe to Swim In

Chlorine is a disinfecting chemical used to keep swimming pools sterile. It is also the cause of various side effects like asthma, dry skin/hair, and red eyes, among other problems.

Some people are also fed up with the cost of buying chemicals for their pool, as well as the hassle of regularly testing their pool water and adding chemicals when needed to ensure the water chemistry is balanced.

It’s a pain in the butt, so why bother? It’s not surprising that some pool owners are wondering if having low or no chlorine in the pool is still safe to swim in. Can they avoid all of these grievances they have with chlorine by simply… not adding anymore chlorine in their pool?

Unfortunately, chlorine is still very much a necessary evil whose benefits far outweighs its risks. You can potentially avoid much of the downsides of chlorine by converting your chlorine pool into a saltwater pool. If you have a smaller pool, such as an inflatable pool, then you can simply drain and refill the pool with freshwater every day.

Keep reading on to learn more about what exactly chlorine does for your pool, what happens if you decide to forgo chlorine, and some possible alternatives to a chlorine swimming pool.

What chlorine does for your pool

To better understand what a pool is like with low or no chlorine in it, you need to first understand what chlorine does, and why it has become the ubiquitous sanitizing chemical in all pools.

Chlorine does four things really well:

  • It disinfects the pool by killing bacteria.
  • It oxidizes which improves water clarity and quality.
  • It kills algae and keeps it from growing and blooming in the pool.
  • It stabilizes the pool water and keeps it at a consistent quality.

Another benefit of chlorine is that, because it can do all of the things mentioned above in one chemical, you are actually reducing the overall chemicals added to your pool.

If you try to have a chlorine-free pool, you will need multiple chemicals to do the same thing that chlorine does, and oftentimes with less effectiveness and similar side effects. Therefore, you are not really solving any of the issues that chlorine has.

Swimming in a low or no chlorine pool

So now that you know what chlorine does, what is it like to swim in an unchlorinated pool?

First of all, the pool water will keep on accumulating bacteria. Each person that enters the pool will introduce their own bacteria, and if they are sick, then their germs can also enter the water.

Even if the water appears to be clean initially, it can already be carrying viruses that can make you ill. You will be at risk of developing a plethora of waterborne illnesses if you decide to swim in a contaminated pool.

You don’t even have to necessarily ingest any pool water, or have it enter your system through your eyes or an open wound. Keep in mind that your skin is porous, and microscopic impurities can pass through it.

In as little as one day, a pool of freshwater can start to turn green due to an algae bloom. Over time, the color will start to turn darker green because of unrestrained algae growth, and eventually it will turn black with an odor that is as pleasant as it looks.

I think that even after just one or two days, when the pool starts to turn green, is when most people would already lose their desire to swim in it.

Then what about other unchlorinated bodies of water?

If you think about it, the ocean and lakes don’t have any chlorine, yet we can safely swim in it. So why is it so bad for swimming pools to be without chlorine?

To be clear, oceans and lakes are filled with bacteria as well. It’s just that they are also always flowing and moving, receiving fresh water and replacing the old water. The water in oceans and lakes are not confined in one area and therefore don’t become stagnant.

There are also many organisms that naturally purify the water by feeding on algae and pathogens, almost like nature’s water filter, so it’s harder for bacteria to spread rampantly.

Alternatives to chlorine pool

Saltwater pool

Saltwater pools have exploded in popularity in recent decades because they are marketed as being able to provide the same level of sanitation as chlorine pools but with less side effects.

Ironically, saltwater pools still use chlorine to disinfect the water. It uses a salt chlorine generator to turn the salt in the water into chlorine, and it does it in small doses (and automatically) so that you aren’t exposed to high concentrations of chlorine at once.

This kills two birds with one stone: you are less likely to experience chlorine’s side effects and the saltwater pool will monitor the pool’s chlorine levels for you.

That said, changing your chlorine pool to a saltwater pool will cost thousands, but it will even out or even save you money long-term because you don’t need to add as much chemicals into a saltwater pool.

Other sanitizing chemicals

Aside from chlorine, you can use Bromine, Baquacil, ozonators, ionizers, and PHMB to sanitize your pool. As mentioned above, these chemicals alone cannot provide the same benefits as chlorine and you often need to add additional chemicals to help sanitize your pool water.

Inflatable pool

If you just want a small pool that you can relax in during the summer with your kids, or perhaps the pool is exclusively for your kids, then you can just get a small inflatable pool, fill it with freshwater, and dump it all out at night and refill it with freshwater the next day.

For a small pool like an inflatable pool, you can more easily justify draining and refilling the pool on a near daily basis, and therefore you never have to worry about adding chlorine to it. That said, the amount of water you end up wasting can add up in the long run.

Photo Credit: Benny Lin (CC BY-NC 2.0)