A crystal clear, sparkling, cooling pool can be the jewel of a beautiful garden. But wait. What is all that slimy green, yellow and black dirt on the side of the pool?! It's every pool owner's worst nightmare: algae. Not only does it ruin the pool's aesthetic appeal, but it also contaminates the equipment and poses a hygiene risk for swimmers.

These are the most common types of algae

Green algae 

This is the most common type of algae that can appear in the pool, but fortunately it is also easy to remove. It typically appears in the hardest-to-clean areas of the pool, like steps or corners.

And how can you spot it? When green algae appears, a slimy, 'slippery' layer forms on the surface of the water on pool walls, or on the steps where there is less water circulation. It spreads quickly and ruines water quality, so you should pay particular attention to it during summer and clean the pool as soon as possible.

Increased water circulation can be one of the most effective ways of preventing algae forming. If algae is already there in your pool, the best way to kill green algae is to chlorinate pool water to disinfect it. Unfortunately, in cases of severe algae presence, only a complete water change and pool disinfection will help.

Yellow, or "mustard algae"

They don't spread as fast as green algae, but are much more challenging to get rid of. Yellow algae often looks like sandy dirt on the bottom or sides of the pool. It usually occurs when the pool water is stagnant, when heavy rain washes organic particulars into the water, or when the PH of the pool is not balanced.

Here again, chlorine shocking will be the solution, but prevention is particularly important to check the chemical balance of the water frequently and keep it at the right level.

You can read more about this in our article below, click on the link.

Black (or blue-green) algae 

This species of algae is otherwise native to lakes, thrives in neglected, high PH, low chlorine and/or poorly filtered pools. Black algae lack protective mucus and therefore penetrate deeper into the layers of the pool.

If left untreated, black algae can cause structural damage to the pool by penetrating deep into concrete and other pool surfaces. It is the most difficult to clean, but not impossible with the right tools.

How can you prevent algae growth?

Algae only need a few hours of sunlight to grow and take over your pool. Several factors contribute to this issue, including low chlorine levels, insufficient pool filtration, or poor water circulation.

Here are some useful tips to prevent algae growth:

• Before using in pool, clean any toys that you have used in natural/tap water before.
• As a preventive measure, apply an algaecide when cleaning the pool following weekly water testing and chlorine shock treatment.
• Vacuum clean the pool regularly.
• Check the filtration system weekly to make sure it's working properly! You should run the filter for 8-12 hours a day.
• Invest in a cost-effective pool cleaning robot to help prevent algae growth.

What is the most effective solution if the problem has already occurred? 

Once the problem has occurred, only a complex and multi-step solution will be effective:

• Weekly chlorine shocks, 
• use of an algaecide after shocking, 
• regular cleaning with a pool cleaning robot, 
• thorough cleaning of walls and stairs, 
• thorough cleaning of tools and toys used in the water.

The best pool cleaning robots to fight algae 

The automatic pool cleaning robot is by far the most cost-effective, easiest and fastest way to clean your pool from all kinds of dirt, including algae. It collects everything from leaves in the pool to fine debris, sand and harmful algae and leaves your pool water christal clear.

What are the most important features of robots that prevent algae growth?

When buying a pool cleaning robot, you should consider the following features of the robot in relation to algae growth:

• Be sure to choose one that cleans all areas of the pool insluding side walls and the waterline. 
• The quality of the filter is crucial, so ensure it can effectively capture tiny particles like algae.
• Active brushes provide unrivalled cleaning power, as they rotate at twice the speed of the robot.

Let's see which types meet these criteria!

1. Dolphin M700 

The top-of-the-range Dolphin M700 is designed to provide unrivalled scrubbing performance on floors, walls and waterlines.

• With the Wi-Fi®-connected MyDolphin™ Plus app, you can program scheduled cycles to suit your needs. 
• The M700's unique sensor measures water temperature and a special sensor (FI) shows filter status on multiple levels. The FI sensor offers multiple levels of filter saturation, allowing for timely filter cleaning, which extends the robot's lifespan.
• The dual drive motor enhances the robot's agility and speed, enabling it to navigate the pool efficiently, regardless of its shape, level variations, or obstacles.
• We've maximised cleaning performance, fitted it with the largest filter basket and optimised its manoeuvrability.

2. Dolphin S400

Discover the exceptional experience of automated pool cleaning with the Maytronics Dolphin S400.

• Control your robot from anywhere, anytime with the new MyDolphin™ Plus mobile app. You can control it remotely via the multi-function power supply or from your smartphone. 
• Ideal for cleaning all kinds of pool floors, sidewalls and waterlines up to 15 m pool length. 
• Its advanced CleverClean™ navigation system adapts to the shape of your pool for maximum performance. Its two types of filters - for normal and ultra-fine dirt - ensure crystal clear water. Its 3-dimensional filter has increased filter capacity. 
• Its Pick-Up feature makes it easy and convenient to lift out.

3. Dolphin S200 

It's the queen of ultra-lightweight robotics, made easier by fast water release. Keep your pool spotless and free of algae with the Dolphin S200 robot, featuring two filtration options to remove both big and fine debris.

The dual brush action and PowerStream™ mobility system ensures efficient operation across the entire pool area, with extra thorough scrubbing on all surfaces - leaving floor, walls and waterlines spotlessly clean.

For further details on selecting a robot, refer to our article: LINK

Aquashop has a wide range of robotic pool cleaners to choose from. Here you will find for sure the right one to keep your pool crystal clear and algae-free for the season!

Previous articles on pool maintenance and cleaning 

This is how I clean my pool: LINK

7 tips for a sparkling clean pool: LINK

How often and how to clean your pool: LINK

5 secrets to an eco-friendly pool: LINK

Have a nice splash!

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