Do Robotic Pool Cleaners Pick up Algae?

Do Robotic Pool Cleaners Pick up Algae

Few things are as revolting as seeing your normally clean and pristine pool developing a green hue. A green pool is a sign of algae growth, which can occur if the water chemistry in your pool water is off, but also if your pool isn’t being cleaned often enough. Thankfully, a pool robot can help you with the latter.

Robotic pool cleaners can clean up all kinds of algae as long as the cleaning filter is capable of picking up particles that are 2 microns large. Furthermore, the longer a pool robot is running, the more likely it can pick up finer particles such as algae as its filter openings keep getting narrower (be careful not to let it get completely clogged).

Given this criteria, there is a possibility that some pool robots are incapable of cleaning up algae in your pool. Keep reading on to learn how you can get a robot cleaner that can get the job done and which ones to avoid.

Why (most) robotic pool cleaners can keep your pool algae-free

First off, you don’t need to have a pool robot. If you’re willing to put in a lot of sweat equity in your pool, then you can manually scrub the pool clean yourself.

That said, most people would rather let a pool robot do this menial work. Pool robots will slowly move around the entire pool, dutifully picking up minute filth particles that have entered.

Since pool robots are automatic, they require no supervision on your part, freeing up time and energy for you to do something else. Just make sure no one is swimming in the pool while it’s running.

Pool robot designs have improved over the years by leaps and bounds. They now come with such features as stronger suction power, hyper-grip tracks, and active brushes. As a result, they can clean up young algae growths before they ever become an issue.

Combine this with an ultra-fine filter capable of trapping particles at least 2 microns large, and your pool will remain clean and pristine.

Let your pool robot clean your pool at least once a day to get rid of dirt particles in the pool water that act as a food source for algae.

Not all pool robots can clean algae

As much as we tooted the pool robot’s horn just now, regrettably, not all pool robots can pick up algae. For instance, if a pool robot only cleans by scrubbing instead of vacuuming, then it cannot get rid of the algae in your pool even if you leave it running all day and night.

With that said, this is becoming less and less of an issue as pool robots with this outdated design are rapidly being replaced by newer models that can skim and vacuum.

Furthermore, many robotic pool cleaners are clearly labeled as unable to clean algae on the box or on the online product page. They aren’t required to do so, so do your research on which ones can and can’t.

To ensure the pool robot you’re eyeing is capable of cleaning pool algae, look for the following criteria:

Criteria for a robotic pool cleaner that picks up algae

Vacuum mode

Algae can be anywhere from 1.5 to 15 microns large, depending on the stage of a colony. When the algae are dense, even a skimmer can easily clean them up. The issue is when algae are separated into finer units where you need a really fine filter to pick them up.

When algae are really fine, between 1.5 to 5 microns, some pool robots may fail to clean them all up. Furthermore, smaller algae cannot be picked up unless the robotic pool cleaner has strong suction capability. Thankfully, many pool robots under $500 meet these criteria.

1 to 2-micron dirt filter

As mentioned above, when algae are around 1.5 micron in size, even most pool vacuum robots will fail to pick them up. More accurately, they will get picked up, but the filter inside will not retain the algae, allowing them to pass through and back into the water.

Narrow permeability filters that are commonly available can pick up particles at 2 microns. This is more than adequate to filter out the majority of algae at a low speed.

If the pool robot is moving too quickly, algae may break down when hitting the filter panel due to the speed, allowing them to pass through the filter. Your best bet is to not only set the robot to move a low speed, but also to leave it running for an extended period of time,

As the filter catches more particulates, its pores will get clogged up, allowing it to pick up particles smaller than 2 microns in size. This semi-clogged filter is great at catching even the smallest algae.

You cannot get the same effect using a bigger filter, so you need to find a robot cleaner that can use 1 to 2-micron dirt filters to pick up all the smaller particles.


Many pool owners prefer a cordless pool robot since cables can get in the way, plus they don’t want any tripping hazards. The disadvantage is that cordless pool robots cannot operate for very long.

A corded pool robot, on the other hand, can run indefinitely, which is very good for picking up all of the algae. As the filter starts to trap more particles and its pores narrow, it further increases its ability to pick up fine algae from the water.

Ideally, you should run a robot cleaner for 50% longer than the recommended cleaning time for your pool. For example, if a pool robot can clean a 500 sq ft pool in 40 minutes, you should run it for 60 minutes (50% longer) to ensure it’s picking up the smallest particles.

Most battery-operated robotic cleaners have a battery life of 60 to 90 minutes. For a medium sized pool, 90 minutes is just about the bare minimum time required to clean a pool of this size.

With a corded pool robot, you never have to worry about its battery-life and can leave it running for hours at a time if you want. That lends itself to a cleaner, algae-free pool.

Floor and surface cleaning

Another consideration you must make is that algae often float along the surface of the pool because it needs sunlight to survive. Even floor algae cannot thrive if there is sufficient sun cover.

When looking for a pool robot for cleaning algae, consider one that can clean both the floor and surface. You can also get two separate cleaning devices, one for each task, if it makes more financial sense to do so.

High water suction rate

I mentioned earlier that a skimmer that moves at a slow pace makes it less likely for larger chunks of algae to break apart and move past the filter. That is why slow moving skimmers are desirable if your goal is an algae-free pool.

However, what you also want is a cleaner with a high water suction rate which allows it to cycle through multiple gallons of pool water a minute. This ensures that all of the algae in the water, including surface algae, gets recycled through the robot’s cleaning system.

One that is meant for a bigger pool

Are you having doubts about your pool robot’s ability to clean your pool? If you have the funds, I recommend you get a pool robot rated for a larger pool. Such units will feature a higher water suction rate and finer brushes.

Furthermore, they are designed to run for longer periods, allowing you to leave it running for much longer to ensure all the debris and particulates are getting picked up. This option is more expensive, but the peace of mind and water clarity it gives you is well worth it.