Why is there Algae in My Pool? (And Why You Shouldn’t Panic)

Understanding what causes algae — and how Penguin Leisure can help you stay in control

If you've noticed algae appearing in your swimming pool recently, you're not alone. It's a hot topic among pool owners right now and for good reason. Algae can seem to crop up overnight, especially as temperatures rise and the sun begins to shine more consistently.

The good news? Algae in your pool doesn’t automatically mean poor maintenance. In fact, it's more common than you might think and with the right approach, it's completely manageable.

What causes Algae in swimming pools?

Algae are microscopic plants that thrive in warm, sunny, and nutrient-rich environments. While chemical imbalance and inconsistent cleaning can contribute to growth, other external factors can also play a big role, including:

• Warm weather and prolonged sunshine – Ideal conditions for algae to bloom rapidly
• Heavy rain and storms – Which can introduce contaminants and dilute sanitiser levels
• High pool usage – Leading to fluctuating chlorine levels and increased organic debris
• Poor circulation or dead spots – Where water sits still and algae can take hold

What type of Algae might you be seeing?

• Green algae – The most common and fast-growing type
• Yellow or mustard algae – Often seen on pool walls, more stubborn than green
• Black algae – Tough and rooted into surfaces, requiring more aggressive treatment

Prevention and treatment: Our proactive approach

At Penguin Leisure, we design our maintenance schedules to actively prevent algae, with regular checks on chlorine, pH, filtration, and circulation. But even with excellent ongoing service, a sudden spike in temperature or an unexpected storm can trigger a bloom.

That’s why we encourage our clients to:

• Stay calm – Algae isn’t a sign of failure; it’s a natural issue we’re equipped to handle
• Get in touch early – The sooner we know about it, the faster we can act
• Trust the process – Some treatments may take time, but we’ll always aim for the most effective and lasting solution

Need help? Just ask.

If you've noticed a change in your pool water, or even just have questions about algae prevention, give us a call. We’re here to advise, support, and keep your pool safe, clean, and sparkling all year round.