Pool owners often see terms like “150μm” or “50-micron filter” when shopping for a robotic cleaner — but what do those numbers actually mean? And how do they affect the cleaning performance?
This post explains the different micron ratings you’ll find in robotic pool cleaner and skimmer filters, what they capture, and how to choose the right one for your pool’s debris profile.
What Is a Micron? 📏
A micron (μm) is one-millionth of a meter. It’s a unit of measurement used to describe the size of particles a filter can trap.
A 200μm filter can catch objects 0.2 millimeters in size — like pine needles, acorns, or small twigs
A 150μm filter is ideal for catching leaves, petals, dead bugs, and general debris
A 100μm filter starts to catch finer dust, broken-down organic matter, and smaller pollen clusters
A 70μm filter handles fine sand, light silt, and wind-blown dust from decks or patios
A 30μm filter captures most pollen, finer silt, and some suspended biofilm residue
A 10μm filter is necessary to trap very fine particles like algae spores or sunscreen residue
The lower the number, the finer the filtration — but also the faster it may clog if your pool has a lot of large debris.
Micron Ratings & What They Capture - A Visual Breakdown 📊
| Micron Size | Debris Type | Example Debris |
|---|---|---|
| 200μm | 🍂 Large surface debris | Small twigs, pine needles, acorns |
| 150μm | 🍁 General pool debris | Leaves, bugs, flower petals, seed pods |
| 100μm | 🌬️ Finer organic debris | Dust, broken-down leaves, light pollen clusters |
| 70μm | 🏖️ Fine silt and dust | Sand, patio dust, fine grit |
| 50μm | 🧼 Light suspended particles | Cosmetic residue, small biofilm |
| 30μm | 🌾 Heavy pollen loads | Tree pollen (oak, maple, pine), suspended plant dust |
| 10μm | 🦠 Algae and spores | Algae spores, sunscreen, chemical cloudiness |
This visual breakdown gives you a clear idea of what each micron rating is capable of filtering. Pair it with the right cleaner and basket type to tackle the specific debris your pool collects.
Typical Filter Ranges by Cleaner Type 🧹
Different pool cleaning tools use different filter ranges, depending on what they’re designed to capture:
Robotic Pool Cleaners 🤖
Above ground models: Most use standard 150μm baskets, ideal for leaves, bugs, and general pool debris. These filters offer a good balance of water flow and effective capture for casual and seasonal cleaning.
Inground models: Most also come with 150μm filters as standard. However, premium models often include dual-filter systems or interchangeable trays — one coarse (150μm) for larger debris and one ultra-fine (10–50μm) for fine silt, sand, or algae. This added flexibility helps tailor the cleaning approach to seasonal debris levels or specific water conditions.
Robotic Leaf Skimmers 🌿
150–200μm mesh trays — ideal for large leaves, insects, and surface debris
Not suitable for capturing sand or fine silt — they work best paired with a floor cleaner
Which Filter for Which Debris? 🧪
Match your filter type to your pool’s environment:
Trees nearby? Expect large leaves and debris — stick to 150–200μm
Windy or dusty location? A 70μm filter helps with fine particles and sand
Battling algae or cloudy water? Use an ultra-fine (10–30μm) filter to trap spores
💡 Tip: Always clean your filters after heavy use. Finer filters clog faster and reduce suction if not emptied regularly.
Can You Swap Filters? 🔄
Many mid-range and premium robotic pool cleaners support filter swapping. Some come with multiple baskets or layered trays, while others offer upgrade options sold separately.
Look for:
Snap-in trays or removable filter cartridges
Models with dual baskets or combo filters (coarse + ultra-fine)
Swapping filters seasonally can help you clean more effectively:
Use ultra-fine filters in spring and fall for pollen and algae
Use coarse mesh in summer when debris is larger and clogging is less frequent
What About Algae and Very Fine Debris?
Algae spores range from 5μm to 30μm, depending on type. Only ultra-fine filters (10–50μm) can trap them mechanically.
However, filters alone aren’t enough to kill algae. You still need:
Proper chlorine levels
Algaecide treatment
Regular brushing and circulation
Use ultra-fine filters to capture what breaks loose after chemical treatment — it’s the final step in a full algae cleanup.
What About Pollen and Seasonal Surface Debris? 🌸
Pollen, flower petals, and seed husks are especially common in spring and early summer. Though not as small as algae, many types of pollen fall in the 10μm to 100μm range — too small for coarse filters to catch consistently.
Maple, oak, pine, and grass pollen often measure 30–50μm
Petals and seed casings may float and clog skimmer baskets — or require a robotic leaf skimmer
If your pool is near trees or flowering plants, consider running a fine or ultra-fine filter during high-pollen months. Skimmers can help reduce surface buildup before debris sinks to the floor.
Compare Cleaners by Filter Type and Micron Rating 🔍
Want to find the right robotic cleaner based on filtration power? Use our filters to compare by:
Micron rating – 200μm to 10μm filters, based on what type of debris you want to trap
Skimmer or cleaner type – distinguish between floor-cleaning robots and surface skimmers
Debris needs – use the chart above to match filters to leaves, pollen, algae, or fine dust
Traction type and pool compatibility – choose between wheeled or tracked models, and match to above ground or inground setups