Can Fibreglass Pools Get Algae Growth?

Taking the plunge into the world of pool ownership is a joyous occasion, a milestone of summertime fun and relaxation. However, it’s not all turquoise waters and poolside parties – pool maintenance can sometimes feel like navigating a minefield of potential problems.

One common question amongst pool owners is whether a fibreglass pool, prized for its sleek finish and durability, is immune to the dreaded green invasion – algae growth. In this comprehensive guide, we’ll tackle the complexities of algae and how they relate to fibreglass pools, empower you with preventative measures and maintenance tips, and arm you with the know-how to tackle algae should they appear in your oasis.

Understanding Algae Growth

Algae are simple, plant-like organisms that can thrive in the most unforgiving of environments – including your pristine pool. Algae spores, which are constantly introduced to the pool via wind, rain, or even on swimmers’ bodies, need only three things to bloom: sunlight, warm temperatures, and nutrients (especially nitrogen and phosphorus).

For the uninitiated, algae growth can seem like a mysterious process. But it’s anything but unforeseeable. Factors such as improper pH and chlorine levels, poor circulation, and dormant pockets of water – those spots rarely kissed by the sun or the pool brush – create perfect conditions for algae.

Benefits of Fibreglass Pools

The smooth, non-porous surface of inground pools sydney is a double-edged sword. On the one hand, it’s much more difficult for algae to gain a foothold on this surface compared to rougher concrete or gunite pools. Furthermore, a smooth surface means that algae, along with dirt and other contaminants, can be cleaned more easily.

Fibreglass pools are also known for their low maintenance requirements. They don’t require frequent re-plastering like their concrete cousins, and the chemical balance in fibreglass pools is easier to maintain due to their surface properties.

Prevention and Maintenance Tips

Regular Maintenance Routines

No matter the pool type, consistency is key. Develop and adhere to a regular maintenance schedule. Skim your pool’s surface for debris daily, brush the walls and floor weekly to prevent algae from attaching, and keep an eye on your pool’s water level. A water level that’s too high or too low can affect your pool’s skimming action.

Proper Water Chemistry

Maintaining balanced pool water is crucial to prevent algae growth. Regularly test and adjust chlorine, pH, alkalinity, and sanitizer levels to ensure optimal conditions. Aim for a pH range of 7.2 to 7.6, an alkalinity level of 80-120 ppm, and a free chlorine level between 1 to 3 ppm for a healthy pool environment. Consider using algaecides if needed, but verify compatibility with your pool’s surface material for effective treatment.

Maintain Adequate Circulation

Your pool’s filtration system plays a vital role in maintaining clean and healthy water by constantly circulating it. It’s crucial to choose a pump and filter that are the correct size for your pool’s capacity. Running the system for the recommended duration each day helps prevent water from becoming stagnant, ensuring a safe and enjoyable swimming environment for you and your family.

Dealing with Algae in Fibreglass Pools

Despite best efforts, sometimes algae can still find a way to thrive in aquatic environments due to factors like nutrient availability and sunlight exposure. When it does, swift and systematic action is key. This can involve adjusting water conditions, such as pH levels and nutrient content, or introducing natural predators like certain fish species that feed on algae. By taking proactive steps to manage algae growth, the overall health and balance of the aquatic ecosystem can be preserved.

Identify the Type of Algae

Algae comes in various forms, each requiring a different approach. Green Algae, commonly found in freshwater, is the most prevalent type and usually responds well to basic treatments such as chlorine. On the other hand, Yellow (or Mustard) Algae thrives in shaded areas and can be more stubborn to clear, often needing specialised algaecides for effective treatment. Black Algae, known for its roots that make it tough to eliminate, poses a challenge and may necessitate rigorous scrubbing and the use of specific algae removal products.

Treatment Methods

For fibreglass pools, it is vital to exercise caution when dealing with chemical treatments to prevent any potential damage to the pool’s surface. To start, manually scrub the affected areas to remove algae buildup thoroughly. Following this, vacuum up the loosened algae debris to ensure a clean pool environment. Implement a shock treatment to temporarily elevate the chlorine levels, a process commonly referred to as hyper-chlorination, and then sustain these heightened levels until all traces of algae vanish. In some cases, the use of an algaecide or a clarifier additive may be necessary to enhance the cleaning process. For expert advice tailored to your specific pool, it is recommended to seek guidance from a professional pool maintenance specialist.

Post-Treatment Prevention

Algae can make a comeback if your pool’s conditions stay favourable, so it’s crucial to balance and maintain your pool’s water chemistry after treatment. To prevent algae growth, consider using an algaecide on a regular basis. Additionally, make sure your filtration system is well-maintained to keep the water clean and clear. Stay on top of your regular maintenance routines, such as skimming, vacuuming, and checking the chemical levels, to enjoy a sparkling pool all season long.


The battle against algae is a continuous one. Addressing and understanding the root causes of algae growth is critical, whether you’re dealing with it in a fibreglass pool or any other type of pool. Remember, a proactive approach to pool maintenance is the best way to ensure you spend more time enjoying your oasis and less time combating unsightly algae blooms.

In the end, the pride and satisfaction of a sparkling, algae-free pool is worth every skimming, scrubbing, and chemical balancing act. And when you’re floating in that crystal-clear water, basking in the sun, those hours of diligent pool care will seem like a small price to pay for that ultimate summer luxury.