A Guide to Pool Chemicals & Pool PH Levels

Measuring pool water Hp value

A Guide to Pool Chemicals & Pool PH Levels

Owning an inground swimming pool in South East Queensland can be great fun, but it also comes with some maintenance, pool equipment, and pool chemistry requirements.

What are the normal pool chemical levels?

The water in your pool is delicate and needs to be at a pH value of between 7.4 and 7.6 to remain healthy and clean, which sits slightly above neutral on the pH scale. If the pH value is too high it can cause itchy skin and other skin irritation. You can usually tell if the pH value is high as your pool will have cloudy water. 

Tips for pool owners: Pool chemical test kits for residential pools can be purchased on the Gold Coast and in Brisbane from Captain Nemos.

Swimming Pool Chemical Balance Guide

If you are someone who feels overwhelmed by the cocktail of chemicals your swimming pool requires to keep the water balanced and avoid cloudy pool water, don’t worry! You don’t need to be a pool maintenance professional or pool cleaner to keep a healthy pool. We’ve provided a quick guide below to the most commonly used pool chemicals and their role in pool maintenance.

Unstabilised Chlorine

This is your basic Chlorine without stabilisers or Cyanuric acid added to it. Cyanuric acid is added to Chlorine to protect it from the sun’s UV rays, so use unstabilised Chlorine without Cyanuric for all indoor pools and spas where there are no UV rays. You may also use it if you need to increase levels of Chlorine for short periods during high pool usage during the summer months.

Dosage: Add 15 grams of unstabilised Chlorine for every 10,000 litres of water to raise by 1 PPM. Dilute the Chlorine in a bucket of pool water first, and then simply disperse it around the pool evenly.  


Stabilised Chlorine

After large water spills or heavy rainfall, both Chlorine levels and Cyanuric acid levels of your pool will be diluted and in need of a top-up. This is your regular maintenance Chlorine for those instances.

Dosage: Add 15 grams of stabilised chlorine for every 10,000 litres of water to raise the Chlorine level by 1 PPM and disperse the same way you would unstabilised Chlorine.


Cyanuric Acid

As you may have figured out already, Cyanuric acid is the “stabilised” part of stabilised chlorine. You add this chemical to your pool water if your chlorine levels are already at optimal levels and want an extra layer of protection to make the chlorine last longer.

Dosage: 100 grams of Cyanuric acid should raise the cyanuric acid levels of 10,000 litres of water by 10 PPM. Firstly dissolve the Cyanuric acid in a bucket of pool water before adding it directly to your skimmer boxes.


Alkalinity Up or Sodium Bicarbonate

Alkalinity up or Sodium Bicarbonate serves as a buffer for rapid changes in pH levels which can lower the effectiveness of your other pool chemicals. It is also used to reduce pool water acidity and increase alkalinity levels.

Dosage: Add 200g of sodium bicarbonate for every 10,000 litres to raise the pool’s total alkalinity by 10 PPM. Add into the water in small increments to not exceed your desired Alkalinity levels.


Hydrochloric Acid

Hydrochloric acid is added to a pool to reduce its pH levels when too high. The liquid is highly corrosive so make sure to wear protective clothing and glasses.


Starting pH Level Per 10,000 Liters
7.6 to 7.8 100ml
7.8 to 8.0 120ml
8.0 to 8.4 200ml
8.4 and above 235ml

We recommend you dilute the Hydrochloric acid in a bucket of water before adding it to your pool. This is to avoid concentrated patches.

Sodium Bisulfate / pH Down Tablets

If you’re not comfortable to be handling Hydrochloric acid, Sodium bisulphate (dry acid) can be used to lower the pool’s pH in the same way.

Dosage: Refer to the dosing information by the manufacturer as each manufacturer has their own tablet size. Simply add the instructed number of tablets to the pool’s skimmers for it to be circulated into the pool.


Calcium Up / Calcium Hardness

Calcium Up increases your pool’s calcium hardness levels to avoid corrosion to your pool surfaces and grout when the water’s calcium hardness levels drop.

Dosage: add100g of calcium up to raise the calcium hardness of the water by 10 PPM for every 10,000 litres. You can directly add the calcium to your pool’s skimmer boxes in small amounts as it dissolves readily.


Calcium Down

Calcium down is the opposite of the above chemical and helps bring the calcium hardness levels down to the optimal levels.

Dosage: Refer to the instructions on the bottle. Make sure you dilute the solution before evenly spreading it around the pool.


Phosphate Remover and Algaecide 

You need these two chemicals to work together to fight and prevent algae in your pool and prevent the water from turning green and murky.

Dosage: Refer to the manufacturer’s recommended dosage instructions.


Clarifying Cubes

You guessed it – these cubes clarify your pool water! The cubes bind with the microscopic particles in your pool so that your pool filter can easily catch them. This is not a quick fix to clear your water but rather a long-term solution. 

Dosage: Add a Clarifying cube to your skimmer basket every month.



Flocculants clarify your pool water quicker than clarifying cubes. They work by actively binding with particles in your pool and sinking them to the bottom. Well at the bottom, you can easily vacuum the particle-balls up.

How to use: Set your filter setting to RECIRCULATE and dilute the Flocculant with pool water before dispersing it around your pool.

Clean swimming pool


In Summary

As well as keeping your pool cleaned by vacuuming and skimming frequently, keep your pool chemicals at the following levels to maintain a safe and healthy swimming pool:

  • pH: 7.4 to 7.6
  • Alkalinity: 100 to 150 ppm
  • Calcium Hardness: 175 to 225 ppm and 225 to 275 ppm for plaster pools
  • For Chlorine or Salt Water Pools: 1 to 3 ppm (I recommend you keep it at 3 ppm)
  • For Bromine Pools: 3 to 5 ppm
  • For Biguanide Pools: 30 to 50 ppm
  • For Mineral System Pools: 0.5 ppm of chlorine

If you still have questions on how to maintain a healthy pool, get in touch with the pool experts at Oasis Pool Constructions.

We are pool professionals and have more than 20 years of experience building inground pools on the Gold Coast, concrete pools in Brisbane and building pools south of Brisbane

Call Oasis Pool Constructions today on 07 5649 9810 or via email: [email protected]

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