Do Pool Robots Pick up Algae?


Microbes are everywhere, yet we still need ad campaigns reminding us to wash our hands. That’s because human disgust is a response to visual stimuli, and we don’t usually get grossed out by what we cannot see. In that way, Algae is special because it is one of the few microbes that become nausea-inducingly visible and that too in one’s swimming pool of all places. But don’t worry, your robot cleaner is ready for the job.

Pool robots pick up algae as long as the cleaning filter is capable of picking up particles that are 2 microns large. The longer a robot runs in a single session, the more capable it becomes at picking up finer particles like algae because its filter openings keep getting narrower.

In this article, you will learn how you can ensure that you get the type of robot cleaner that picks up algae. For this, the post goes over the recommended filter size, usage duration, and operating specs that will help you get rid of the pool algae. But since most pool robots do pick up algae to some extent at least, let’s look at the few you need to avoid.

Robots that cannot pick up algae

While the traditional motorized skimmers are being phased out in favor of new pool cleaning robots that can vacuum and skim, some models of skimmer robots are still available online and in some pool shops. 

If you get a pool robot that cleans with motion instead of vacuuming, your pool algae will not get picked up. Such robots can only tear apart the algae temporarily, and the colony of microbes joins once the skimmer has moved through it.

That said, your chances of getting such a robot cleaner are pretty low since they are being phased out. Nowadays, pool cleaning robots that cannot vacuum algae are explicitly labeled as unable to do so, though this isn’t mandatory. To make sure your pool robot can efficiently and definitively get rid of the algae in your pool, you have to ensure that it matches certain criteria.

Pool cleaning robot criteria: how to get a robot that picks up algae

If you get high-quality pool robots, the odds of landing one that picks up algae are quite high. All you need to do is double-check that the pool has the specs covered in this section. You might be getting a new robot exclusively to remove algae from your pool. The following criteria will help you ensure that the product you get isn’t useless at getting rid of algae.

Vacuum mode

Depending on what stage a colony is at, algae size can be anywhere between 1.5 microns to 15 microns. When the algae are dense, even certain skimmers can pick them up. In most cases, though, the algae are separated into finer units until it reaches 1.5 microns to 5 microns. 

At this stage, some vacuums might fail as well, the reason for which is explained later. It is worth noting that smaller algae cannot be picked up unless the robot has strong vacuum suction. Fortunately, many options under $500 fulfill this criterion.

1 to 2-micron dirt filter

As mentioned earlier, when Algae breaks down to a 1.5-micron size, it cannot be cleaned even by most vacuum robots. It gets picked up, but the filter panel inside the robot is not narrow enough to retain the algae. The most common narrow permeability filter can pick up particles at 2 microns. This is more than enough to get rid of the bulk of the algae at a low speed. 

If the robot is moving too fast, the algae will break down because of the speed of the water hitting the filter panel. The best solution to get rid of algae with a 2-micron filter is to keep using the robot for an extended period. 

As the filter panel catches dirt and dust, its pores get clogged, reducing its permeability from 2 microns. This “clogged” filter is great at holding on to algae. You cannot create such a narrow opening in bigger filters, so you have to start by opting for a robot cleaner that can pick up 2 micron or smaller particles.

Extended usage capacity

Cordless robot cleaners are preferred by pool owners who have kids because cables can be messy. But a cleaner with a cord can run indefinitely, which is good for picking up algae. As a filter keeps operating, it becomes more efficient at picking up finer particles. Ideally, you must have a robot cleaner that can go 50% over the recommended cleaning time for your pool.

For instance, if you’re meant to clean a 500 sqft pool in 40 minutes, you should be able to go over by half of 40 (20 minutes). Most battery-operated robot cleaners can run between 60 and 90 minutes. The 90-minute mark is the sweet spot for picking up algae in a medium-sized family pool. For smaller pools, getting an expensive high mAh battery robot might not make sense. It is better to use a pool cleaning robot with a long enough cord to cover the floor.

Floating + floor cleaning

Another thing you must note is that algae float at the top of the pool because it needs sunlight to survive. Even pool floor algae cannot propagate if there’s enough sun cover. When opting for a pool cleaning robot, you need to look for an option that doesn’t exclusively clean the floor. You should either get a pool cleaner that floats and cleans the surface as well or should get two separate cleaning devices with one skimming the surface and one vacuuming the floor.

High water suction rate

Skimmers that move at a low pace prevent larger chunks of algae from breaking apart and moving past their filter panel. That’s why floating skimmers that move slowly are desirable. But when it comes to a vacuum robot, you want to get a cleaner that cycles multiple gallons per minute. This is the only way to make sure surface algae gets cycled through the robot’s cleaning system.

Best practices for buying pool cleaning robots to clear algae

Now that you know the type of swimming pool cleaning robot you need to get rid of algae let’s look at what you must do when shopping for a robot to maximize the chances of making your pool algae-free. Here are the tips that will help you avoid a robot that is useless against algae.

Check the reviews

It goes without saying that you should check the reviews of a product you intend to buy online. But in this case, you have to be more specific in your search. Sites like Amazon allow verified buyers to post detailed reviews. They are able to include images and videos even. But you’re not going to look for images. 

You will use the Control (Ctrl) and F buttons to open the webpage word finder. In the search bar, type “algae” to see whether the manufacturer or reviewers have said anything about algae. In case the word has a match on the page, it will be either in reference to the robot not being able to pick up algae or it being great at picking algae.

Ask a question

If you try Ctrl+F and do not find the word “algae” on the product page and not even on the “all reviews” page, you have the option to ask a question. Sellers usually answer the quickest, but other users also have the option to give their 2 cents. 

You can either ask, “does this pick up algae?” or “what is the smallest micron particle this can pick up?” For the former question, the seller or a customer will give a straightforward yes or no answer. In the case of the latter question, you will learn whether the robot’s filter is capable of picking up a 1.5-micron particle.

Get a robot meant for a bigger pool

Finally, you can ensure that you’re giving your pool the best shot of being algae-free by getting a pool robot meant for a larger pool. Such robots have a higher suction capacity and finer brushes. More importantly, they can run for longer periods, which can help their filters get more efficient at catching algae. This option is slightly more expensive but is well worth the price if the result is that you don’t have to manually fish out the algae.

Other ways to get rid of algae

While pool robots can remove algae, they aren’t the only algae removal solution. In fact, a bulk of algae removal is done by the pool’s own filter. The steps below illustrate how you can get rid of algae in your pool without a robot cleaner picking it up for you.

Kill the algae

The first step in getting rid of algae is to ensure it isn’t propagating. Algae cells are microscopic and invisible, and if every chunk of visible algae you remove is simultaneously replaced by invisible algae, then your pool can never be free of algae. 

To ensure that your pool isn’t perpetually inhabited by algae, you need to use an algaecide like HTH Super Algae Guard to kill the algae. Mixing such a product in the water means you won’t be using the pool yourself either. But fortunately, this takes around one day to get homogenized and cycled out.

Super Algae Guard is the highest-rated product of its kind on Amazon, with over 6000 reviews and ratings coming to a global average of 4.6 out of 5 stars. Plenty of users have posted pictures in their reviews applauding HTH for presenting a product that can clear a pool. 

It works with vinyl liner and in saltwater as well, giving it an enviably wide range of compatibility. Some algaecides take so long to settle that you have to wait 24 hours after adding them to the pool before you can swim. With this product, your pool is ready to swim in 15 minutes.

Scrub the surfaces

The next step is removing algae without a robot is to physically scrub the surfaces to which the algae seems anchored to. As gross as the surface algae might look, it is the easiest to get rid of. The chunks that are lodged between tiles or are stuck to the walls are the hardest to remove because they do not circulate. 

Scrubbing vigorously using an algae brush like Aquatix Pro Heavy Duty Pool Brush can help. While any brush can work for this purpose, we prefer the Aquatrix one because of its stainless steel bristles. It is meant to scrub off stains, which makes it perfect for removing algae which is easier to scrub away than most stains. This product has a global average rating of 4.4 out of 5 stars from an aggregate of over 1000 reviews and ratings, lending it further credibility.

Run the pool pump for 24 hours

Once you have removed the algae anchored to your pool walls and floor and have added algaecide to ensure it is dead and doesn’t propagate, all that’s left is trapping the dead algae in a filter. For this, you can run your pool pump for 24 hours. Usually, all of the pool water goes through the circulation system once every 24 hours. If your pool filter can catch 1.5-micron particles, the algae will be trapped and removed in the backwashing process.

How to prevent algae

From the above steps, you can tell how hectic algae removal can be. Here’s how you can ensure that it doesn’t become a regular part of your pool maintenance routine. The following best practices will keep your pool from accumulating algae.

  • Ensure that pool circulation is running properly and the pool water isn’t stagnant. 
  • Shock the pool every week or add enough pool salt
  • Schedule regular brushing sessions
  • Use a sun cover whenever possible

Final Thoughts

Pool robots pick up algae if they have the appropriate filter. Similarly, if your pool pump has the right filter, it can also trap algae. What remains is scrubbing it off of the surfaces where it is anchored. For that, you can use steel bristle brush or a robot with a fine brush. Either way, as long as the algae get removed from the surfaces it is attached to, it will be easy to clear out with a pool pump or a robot cleaner.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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