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Confused by the cocktail of pool chemicals required to keep your pool water clean and balanced? Get a quick overview regarding the most used pool chemicals and their role in pool maintenance.


Probably the best-known pool chemical is chlorine. This sanitiser is a highly efficient disinfectant used in pool water to kill disease-causing pathogens, such as bacteriaviruses, and protozoans. It comes in liquid, powder, and tablet forms. Plus your salt water chlorinator produces it every time the pump turns on.

Fun fact: the “pool smell” isn’t caused by chlorine – it’s the lack of chlorine that’s creating the odour

That’s because when chlorine removes organic matter in the water such as skin cells and body oils, it leaves behind a smelly residue called chloramines. That smell means existing chlorine has been depleted – and a ‘shock’ is required.


Shocking a pool is the act of removing smelly organic residue or chloramines and reviving inactive chlorine. Shocking can be done with an Oxyshock treatment. When added to the pool, Oxyshock disintegrates bacteria, algae and viruses, so they either die or can-not multiply. We recommend Oxyshock is used about once a week or every two weeks, depending on pool usage.


This is an alternative to chlorine, but typically used in spas with warm water. Spas tend to have a bigger pH range than pools do. Bromine works as an effective sanitiser is a broad pH range so it is more effective in this type of environment.


The sun’s ultraviolet rays can quickly remove chlorine from the water. Cyanuric acid – also known as Stabiliser, is used as a sunscreen for chlorine. It helps by stabilising, or protecting, the chlorine from sunlight. However, there is a limit to the amount of Stabiliser that can be in the pool: too much can also slow the destruction of bacteria. Some chlorine products come with Stabiliser added.

pH Balance

Water balance is typically achieved when it’s tested at a neutral pH level of 7.0. Below that means the water is on the acidic side; above means it’s alkaline. Ideal pH levels in a pool should be between 7.4-7.6. Pool chemicals will affect the water’s pH level, which requires the use of a pH balancer to bring it back to as close to neutral as possible.

What do pH balancers do?

Buffer – Increases the alkalinity & decreases acidity

Hydrochloric acid – Decreases alkalinity & increases acidity

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Calcium Chloride

Your pool requires a minimum level of calcium hardness before molecules start to look elsewhere for its minerals and eat away at your tile and metal. Calcium chloride will increase calcium hardness.


Often copper-based, this product serves as a preventative barrier against algae. After the pool has been shocked, algaecide is added to keep the algae from returning.


These are polymers that coagulate particles in the water. They work by trapping particles in the filter. Clarifiers can be made of a number of different chemicals, including ammonium chloride, crab shell extracts, and enzymes.


Similar to a clarifier in that it attracts and binds particles together, flocculents sink the particles to the pool floor instead of running them through a filter. For that reason, the filter needs to be off during those eight to 12 hours while the flocculent is at work. After the particles cover the bottom of the pool, they need to be vacuumed to waste. A pool must have a waste line to allow the use of flocculants.

Please always be aware that chemicals should be locked away from children and animals, and stored separately. For proper handling and usage/dosage of pool chemicals, please refer to the appropriate manufacturers instructions.

Want to know more?

To learn more about pool chemicals talk to the team at Pool Doctor, or bring in a pool sample for all your water testing and maintenance needs. Contact us for more.

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