Pool owners across the world know that chlorine equals a clean swimming pool and a happy family. Chlorine is your best friend and the first arrow to fire in the event of an algae attack. 

However, you may have heard the term, free chlorine and are pondering the difference between chlorine and free chlorine. 

Well, that’s an excellent point to ponder, and thankfully comes with a simple answer.

What is free chlorine?

When you pull out your trusty pool testing kit and check your chlorine levels, the result you’re looking for is actually, the free chlorine level in the water. 

Chances are, you have one of those floating chlorine dispensers which dole out the appropriate amount of chlorine during the month. As this product dissolves in the pool water it changes in structure and becomes hypochlorous acid. 

This weak acid breaks down further and combines with the oxygen in the water, now becoming hypochlorite. These two chemicals, hypochlorite and hypochlorous acid together make up free chlorine.

While in this state, these two chemicals are free to react with swimming pool contaminants and break them down; these are our little chemical workhorses.

However, when this process starts and they combine with perspiration, oils, dirt, and urine, the active chemical changes into chloramines. Chloramines give off that “swimming pool smell” which many people mistake for high levels of chlorine but are, in fact, an indication that the chlorine levels are working hard and on the fast track to being depleted.

So what does this all mean?

Well, when we’re testing our pool water we are looking for chlorine levels between 1 – 3 ppm of free chlorine. This is what attaches to pool contaminants and breaks them down. If your free chlorine levels are low, then there are not enough water warriors available to keep your pool sanitised.

Do you need assistance in maintaining your pool? Call Pool Spa for products and advice.