Why Pool Robots Suck At Picking Up Algae

Pool robots are powerful. They’re Arnold Schwarzenegger for your backyard Oasis. The Terminator for dirt and debris that finds its way to the bottom of your swimming pool.

They can do a lot of amazing things, and in some cases, they can clean a dirty pool in less than a few hours.

With that being said, there are some things that pool robots simply cannot do. For one, they can’t pick your kids up from the soccer game. And they can’t pick up your bar tab.

But what about algae? A pool robot has to be able to pick up algae. Right?

Kind of, sort of, not really.

In this post, we’ll share what a pool robot is primarily used for. We’ll also cover why pool robots are not the best solution for removing algae.

What a pool robot is designed for

First, let’s dive into what pool robots are good for.

Pool robots are time savers and great for everyday maintenance.

Pool Robot with Leaves in Basket

They’re designed with a motor, which can be powered by an electrical source, or part of your pool’s filtration system. This motor propels the robot all around your pool.

Pool robots also come with a bag or basket, which is used to trap dirt, leaves, grass clippings, and other debris that it sucks up.

The bags that capture the dirt have tiny holes in them. These are designed to let water flow through the cleaner.

Once the bag gets filled with debris most robots will power off. At that stage, you need to remove the robot from the pool, empty the basket and hose it off.

It’s some maintenance, but it’s a heck of a lot simpler than having to lug a hose, pole, and vacuum head out of your shed every time you see a bit of dirt in your pool.

Why pool robots aren’t an effective solution to getting rid of algae

Now that we know pool robots are designed mainly for routine cleaning, let’s cover why algae is more difficult to clean.

Algae are very small

In terms of size, algae are much smaller than leaves or dirt. To put it in perspective, algae is approximately 1.5 to 15 microns. For comparison, a human hair is about 70 microns.

This makes algae more challenging for a pool robot to vacuum up. In fact, algae are so small that they can easily pass through the mesh on most pool robot bags.

There are some pool vacuums that have bags that claim to pick-up algae. These cleaners have very fine mesh that captures the algae cells.

The downside to these vacuums is that they can get clogged easily and need to be cleaned frequently.

Algae are buoyant

Algae are also buoyant, which means they often float to the top of the water.

This makes it difficult for a pool robot to vacuum them up from the bottom of the pool. If the algae aren’t on a hard surface, or on a surface that your pool cleaner can reach (like the walls of your pool), it’s likely that your pool robot will miss it.

Algae can quickly regrow

Another reason why pool robots aren’t an effective solution to remove algae is because they can quickly regrow.

Algae are single-celled organisms. This means that they can reproduce rapidly, and a small population can quickly turn into a large one.

If you’re not diligent about vacuuming up the algae cells, they will continue to multiply and spread throughout your pool.

You might be able to vacuum up a large majority of the algae cells. But, if even a few cells are left behind, they can quickly turn into a full-blown algae bloom.

Algae can be difficult to kill

Even if you do manage to vacuum up all of the algae cells, they can be difficult to kill. This is because some algae can go into a dormant state when they’re not in water.

When the conditions are right (i.e., there’s moisture and nutrients present), the dormant algae cells can come back to life and start growing again.

This means that even if you think you’ve gotten rid of all the algae cells, they can come back and start growing again.

To effectively kill algae, you will need to create an environment that’s inhospitable for them to grow. This can be done by using algaecides and shocking your pool to increase chlorine levels.


While pool robots can do some pretty amazing things, they’re not an effective solution to completely getting rid of algae.

This is because they’re not designed to vacuum up microscopic particles, they can miss floating algae, and they can’t kill algae cells.

If you’re dealing with an algae problem, your best bet is to use algaecides and balance your pool water levels. These methods will create an environment that’s inhospitable for algae to grow.

If you have any questions about pool robots or algae, feel free to post them in the comments section below.

About the Author

stefan schulzStefan Schulz is the founder and owner of PV Pool Cleaner. He spent his college years working at Niagara Pools and Spas, one of the largest Swimming Pool and Hot Tub Dealers in the Eastern United States.

Today, he utilizes his background, experience as a pool owner, and the resources of his digital marketing agency, Orpical Group, to generate informative and engaging content for pool owners everywhere.