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Pool Shop Australia Pool Shop Australia
Feb 29, 2024

Why is My Pool Green?

Having a green pool can be a frustrating experience, but understanding the reasons behind it can help you tackle the issue effectively. There are several common causes of green pool water, ranging from algae growth to imbalanced chemical levels.

Let's explore why your pool might be turning green and how to fix it:

Algae Overgrowth


One of the primary reasons for green pool water is algae overgrowth. Algae thrive in warm, stagnant water with low chlorine levels. If your pool isn't properly sanitised or if the chlorine levels drop too low, algae can quickly take over, turning your pool water green. Algae come in different types, including green algae, which give the water its green tint.

Imbalanced Chemical Levels


Maintaining proper chemical balance is crucial for keeping your pool water clear and healthy. When the pH, alkalinity, or sanitiser levels are out of balance, it creates an environment where algae can flourish. Low chlorine levels, in particular, can lead to algae growth and green water. Regularly testing and adjusting chemical levels can help prevent this problem.

Lochlor Tropiclear Pool Algaecide

Poor Filtration and Circulation


An inefficient filtration system or inadequate circulation can also contribute to green pool water. If your filter isn't effectively removing debris and contaminants from the water, it can provide nutrients for algae to grow. Additionally, poor circulation can create areas of stagnation where algae can thrive. Ensuring your filtration system is properly maintained and optimising water circulation can help prevent algae growth.

Environmental Factors


Environmental factors such as sunlight, heat, and debris can also impact the clarity of your pool water. Sunlight can promote algae growth, especially if the pool isn't adequately shaded. Leaves, dirt, and other debris can introduce nutrients into the water, fueling algae growth and discolouration. Taking steps to minimise these environmental factors, such as using a pool cover and regularly skimming the surface, can help keep your pool water clear.

Lack of Regular Maintenance


Regular maintenance is essential for keeping your pool water clean and clear. Neglecting tasks such as brushing the pool walls, vacuuming debris, and maintaining proper chemical levels can lead to water quality issues over time. Establishing a consistent maintenance routine and staying proactive about addressing potential problems can help prevent your pool from turning green. Check out our essential tips for regular pool cleaning and maintenance.


Dolphin X40 Plus - With free swivel cable and caddy


How to fix a green pool:

Shock Treatment


If your pool water has turned green due to algae overgrowth, shock treatment can help kill off the algae and restore clarity. Shocking involves adding a large dose of chlorine to the water to raise the chlorine levels quickly and effectively eliminate algae. Follow the manufacturer's instructions for proper shock treatment dosage and application.

Brushing and Vacuuming


Brushing the pool walls and vacuuming debris from the bottom can help remove algae and other contaminants from the water. Manual brushing and vacuuming, combined with proper filtration, can improve water clarity and prevent future algae growth. Be thorough in your cleaning efforts, paying attention to corners, steps, and other areas where algae can hide.

Filter Maintenance


Ensure your filtration system is operating efficiently by cleaning or backwashing the filter regularly. A clean filter can effectively remove debris and contaminants from the water, helping to prevent algae growth. If your filter is old or damaged, consider replacing it with a new one to improve filtration performance.

Pentair Side Mount MPV Deep Bed Filter 1.0m dia. 1.2m depth. 65mm MPV, 250kPa

Balance Chemical Levels


Test your pool water regularly and adjust chemical levels as needed to maintain proper balance. Focus on maintaining adequate chlorine levels to prevent algae growth and keep the water sanitised. Adjust pH and alkalinity levels as necessary to optimise water quality and clarity.

Improve Circulation


Promote better water circulation by running your pool pump and filter for an adequate amount of time each day. Consider installing additional circulation equipment, such as a booster pump or a robotic cleaner, to improve water movement and prevent stagnation.


A green pool can be a sign of various underlying issues, including algae overgrowth, imbalanced chemical levels, poor filtration, and environmental factors. By understanding the causes of green pool water and following proper maintenance practices, you can effectively restore clarity and enjoy a clean, healthy swimming environment. Regular testing, cleaning, and treatment are key to preventing green water and maintaining optimal pool conditions throughout the swimming season.

About Pool Shop


Pool Shop is one of Australia's leading suppliers of pool and spa products, offering a wide range of essentials like cleaners, pumps, lights, chlorinators, filters, chemicals, spare parts, and more. We stock the highest quality products as authorised sellers of leading brands such as Zodiac, Astral Pool, Maytronics, Hayward, Madimack, Polaris, Pentair Onga and more. With a price match guarantee and fast delivery, we ensure a seamless shopping experience.

Visit our shop in Unanderra near Wollongong for personalised service and expert advice or order online.

Contact us on support@poolshop.com.au or call 02 9137 8914.