When shopping for a robotic pool cleaner for your inground pool, you’ll quickly come across the term “active brush.” But what does it really mean—and is it worth paying extra for?
Inground pools come in many shapes, finishes, and cleaning needs. Whether your pool has textured plaster, smooth vinyl, or glossy tile, the type of brush on your robot can dramatically affect how well it cleans.
In this post, we’ll break down the differences between active vs passive brushes, how each affects performance, and when passive may be good enough.
🔄 What’s the Difference Between Active and Passive Brushes?
The brush system on a robotic pool cleaner is responsible for loosening debris from the pool surface so suction and filtration can pick it up efficiently.
Active Brushes
Mechanically powered by a motor, often rotating independently of the drive motor
Spin rapidly to scrub surfaces as the robot moves
Break up grime, algae, biofilm, and stuck-on dirt that suction alone won’t remove
These brushes are found on premium and mid-range robotic models. They enhance deep cleaning—especially for pools with plaster, tile, or pebble finishes.
Passive Brushes
Non-motorized, often fixed rubber blades or rollers
Agitate surfaces through contact and movement
Rely on suction and navigation to pull debris free
While simpler and cheaper, passive brushes don’t offer the same scrubbing power as active ones. They’re often found on entry-level or lightweight models.
🟦 Recommended Reading: How Robotic Pool Cleaners Actually Work
🧱 Why Active Brushes Matter for Inground Pools
Inground pools are typically built with durable materials like plaster, concrete, pebble, or tile, which can accumulate oils, biofilm, and algae over time. These surfaces aren’t always smooth, and debris can cling tightly.
Active brushes help scrub off sticky substances at the waterline and floor. They’re especially effective in tackling:
Algae in shaded corners or crevices
Pollen and sunscreen residue on walls
Slippery biofilm buildup near steps and ledges
For larger pools or pools with textured finishes, an active brush setup ensures cleaner surfaces with fewer missed patches.
🟦 Recommended Reading: Do Robotic Pool Cleaners Handle All Pool Surfaces?
🏊 When Passive Brushes (or None) Are Good Enough
Not every inground pool demands aggressive scrubbing. If your pool is maintained consistently and uses gentle finishes, a passive system may be all you need.
Passive brush systems can work well when:
The pool is vinyl-lined and smooth, which doesn’t trap dirt easily
The pool is cleaned regularly (3–5 times per week)
Water chemistry is well-balanced, preventing algae or biofilm buildup
You use a robotic surface skimmer to handle floating debris and reduce load
This setup can be especially cost-effective for homeowners who prefer simplicity and maintenance-free units.
🟦 Recommended Reading: Do You Really Need a Smart Cleaner for Inground Pools?
🧠 Consider These Pool Factors
Your pool’s finish, debris type, and maintenance schedule all play a role in whether active brushes are necessary.
Pool Surface Type
Plaster, tile, or pebble = Best with active brushes for deeper scrubbing
Vinyl = Passive brushes are generally fine for daily cleaning
Debris Type
Algae, sunscreen, and oily residue = Active brushes help remove clingy contaminants
Leaves and grit = Focus more on suction strength and filter access
Cleaning Frequency
Frequent cleaning (daily or every 2–3 days) = Passive may keep up
Occasional or weekly cleaning = Active brushes are more effective after debris sits for days
🟦 Recommended Reading: Robotic Cleaners for Leaves, Sand, or Fine Dust
🧪 Let’s Explore Real-Life Conditions
Here are four real-world scenarios that show when an active or passive brush system makes the most sense:
🏡 Pool Owner 1: Shady, Tree-Lined Pool
Mark has a plaster inground pool shaded by large trees. Leaves, algae, and biofilm are constant issues. He runs his cleaner twice a week. An active brush system gives him the power to keep buildup under control.
🏖️ Pool Owner 2: Sunny, Smooth Vinyl Pool
Tina’s backyard gets full sun, and her pool has a smooth vinyl liner. She uses her cleaner daily and rarely sees algae. A passive brush model works just fine for her and keeps costs down.
🧽 Pool Owner 3: Family Pool with Heavy Use
Alex has three kids and hosts weekend gatherings. Oils, sunscreen, and grime collect fast. He needs a cleaner with active brushes to keep the pool fresh and clear throughout the week.
🧳 Pool Owner 4: Part-Time Vacation Property
Nina’s plaster pool is cleaned once a week while she’s away. It tends to build up algae and dust. She opts for a model with active brushes to reduce the need for manual scrubbing on her return.
✅ Final Advice
If your pool tends to collect sticky, fine, or clinging debris—especially on rough surfaces like plaster, pebble, or tile—choose a robotic cleaner with active brushes. The motorized scrubbing action will save time and boost overall cleanliness.
However, if your pool is well-maintained, smooth-surfaced, and doesn’t face heavy grime, you may do just fine with a passive system. This is especially true for smaller inground pools or those cleaned daily with proper water balance.
When in doubt, look at your pool’s surface type, debris type, and cleaning schedule—that’ll help guide your decision.
🟦 Recommended Reading: What Do Pool Cleaners Actually Clean? Floors, Walls, Waterlines, and More
🔍 Compare Robotic Cleaners by Brush Type
Robotic Pool Cleaner Brush Type for Small Flat-Floor Inground Pools
If you have a small, flat-floor inground pool, you don’t necessarily need a premium robotic cleaner with active brushes. Basic floor-only robots — originally designed for above-ground pools — can get the job done. These units have lower flow rates, smaller batteries, and no active brushes (some use passive brushing, most none at all). That means they won’t scrub algae or oils, but when paired with a leaf skimmer and a handheld vacuum, they can provide affordable, reliable floor cleaning for smaller pools.
Inground Robotic Cleaners with Active & Passive Brushes
These robotic pool cleaners are designed for inground pools of all sizes — small, medium, and large. They provide full coverage across the floor, walls, and waterline, with most models using active brushes to scrub pebble, gunite, vinyl, fiberglass, and tile surfaces. Combined with higher flow rates, stronger suction, and advanced tracking systems, they’re built to handle larger areas and more diverse cleaning needs.
Compare More Inground Robotic Pool Cleaners by Brush Type
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- Corded and cordless pool cleaner models
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