It’s common knowledge that chlorine keeps pools safe for everyone enjoying their summer by swimming and splashing.
But how?
Chlorine is, by itself, a smelly, noxious, potent, and even dangerous chemical. It bleaches clothing, skin, and hair. It can corrode and wear away certain plastics.
But in a small dose it can keep all of us safe from many common diseases could be spread in a swimming pool.
And in smaller doses, it even helps keep our drinking water safe.
The Pool as Petri Dish
Any pool of water, all by itself, is a sort of petri dish. Left untreated, standing water can quickly grow moss and mold, attract mosquitoes and other pests, and house harmful microbes.
By absorbing abundant available sunlight, these pests and plants can quickly overwhelm a pool, pond, or even a small lake.
Many diseases that once commonly struck populations that shared swimming spots are treated by chlorine. Among these are E. coli, salmonella, and a range of other bacteria that cause diarrhea, sore throat, and even the highly contagious illness known sometimes as foot and mouth disease.
So What Does Chlorine Do?
The person who is responsible for caring for your local pool can use one of many different types of chlorine-based compounds. This includes a type of chlorine gas, liquid bleach, or even something called chlorinated isocyanurates.
Each of these, when mixed with water at the appropriate ratio, form something called hypochlorous acid.
Wait! We are swimming with acid?
That seems worse than water with plants and insect eggs in it.
Well, no.
When added at a healthy ratio, based on the surface area and depth of the pool, you won’t suffer any ill effects from a chlorinated pool. Instead, the pool will simply have a clean, watery smell. More importantly, there won’t be floating plants or insects except the occasional bug who unluckily falls into the pool.
What if there’s too much or too little chlorine?
It can’t happen that sometimes the person in charge of the pool gets the formula wrong and put in too much or too little chlorine.
With too much chlorine, swimmers might complain of a chlorine smell, itchy skin, or excessively red or burning eyes. The pool might appear also to have a cloud inside it, so that distant swimmers and the bottom of the pool are hard to see. Also, wet surfaces might feel a little slick to the touch.
Red eyes by themselves are not a reliable sign of overchlorination, though. Even the right amount of chlorine can irritate your sensitive eyes after a few hours of swimming with your eyes open underwater.
With too little chlorine, everything might seem fine at first. But as the day progresses, especially if there are many swimmers, the water will quickly start to get an earthy smell as it collects sweat, dirt, microbes, and yes, urine and feces. Sure, they are in there in traces that are too small to see, but not too small to be dangerous, or even too small to be smelled.
So it is important to get the ratio just right.