When your Dolphin robotic pool cleaner starts leaving behind fine dust or algae after a cycle, the culprit is often the filter. Standard baskets capture leaves and pebbles, but ultra-fine variants trap microscopic particles that cloud your water. In this guide, we break down eight aftermarket ultra-fine filter options that outperform the original equipment, helping you decide which upgrade delivers the clearest results for your pool in 2026. Whether you own an S50, Nautilus CC Plus, or Active 20, there is a replacement set designed to fit without hassle. For more on maintaining peak performance, also check our review of the polaris 9650iQ sport vs VRX iQ plus.
Pros
- High-efficiency microfiltration captures fine dirt, sand, and leaves for pristine pool water.
- Works with a wide range of popular Dolphin robot models, reducing the need for multiple filter types.
- Easy to clean and maintain with no special tools required.
- Affordable price compared to manufacturer replacement filters.
- Solid build quality with lightweight yet sturdy plastic construction.
Cons
- Not compatible with Dolphin Nautilus CC Pro or CC Supreme models, limiting its use for newer variants.
- Older versions of Active 10 or S50 may require removal of a plastic piece for proper fit, which could be inconvenient for some users.
- As an aftermarket part, it may not perfectly match OEM quality or warranty coverage.
The Ulticor Ultra Fine Filter Basket is an aftermarket replacement designed specifically for a wide array of Dolphin robotic pool cleaners. It is an ideal choice for pool owners who already own compatible models such as the Dolphin S50, S100, Active 10/15, Echo, T15, T25, Proteus DX3, Saturn, Cayman, Escape, and others. This basket is not intended for the Nautilus CC Pro or Supreme versions, so buyers should verify compatibility before purchasing.
What sets this filter apart is its microfiltration technology, which captures even the tiniest debris particles. In real-world use, this translates to a noticeably cleaner pool with clearer water, as fine dirt, sand, and pollen are effectively trapped. The basket is easy to rinse and clean every four to six weeks, maintaining peak performance without hassle. Users report that it fits snugly and works reliably cycle after cycle.
The design is straightforward: a white, lightweight plastic basket measuring roughly 9x5x7 inches. Build quality feels solid for an aftermarket part, though it may not have the exact finish of an OEM component. The inclusion of installation tips for older Active 10 or S50 units (which may need a small internal plastic piece removed) shows attention to compatibility details. A video guide is available upon request to assist with that adjustment.
Potential drawbacks are mostly centered on fitment limitations. Owners of Nautilus CC Pro or Supreme will need to look elsewhere. Also, the need to modify older robots could be a minor inconvenience for those not comfortable with simple DIY tasks. However, for the vast majority of compatible users, installation is plug-and-play.
Overall, the Ulticor Ultra Fine Filter Basket offers excellent value for money. It delivers superior filtration at a lower price than official replacements, while covering a wide range of popular Dolphin models. If you own one of the listed robots and want to keep your pool sparkling clean without breaking the bank, this filter is a smart buy.
Pros
- Ultra-fine filtration traps even tiny particles for superior water clarity.
- Easy numbered installation system reduces setup time and guesswork.
- Washable and reusable design offers long-term value and eco-friendliness.
- Broad compatibility with many Dolphin and Maytronics robotic pool cleaner models.
- Sturdy build quality withstands regular use and cleaning without tearing.
Cons
- May require more frequent cleaning than standard filters due to ultra-fine mesh trapping more debris.
- Not compatible with all Dolphin models; double-check compatibility before purchase.
- Some users may find the initial fit slightly tight on certain cleaner baskets.
The Henkgo ultra-fine filter panels are a direct replacement for the OEM part 9991467-R4, designed specifically for Dolphin robotic pool cleaners. These pleated cartridge filters are ideal for pool owners who want to maintain sparkling water without frequent skimming. They fit a wide range of models including the S200, Active 20, Proteus DX4, M600, and many more, making them a versatile upgrade for most Dolphin owners.
Standout features include the ultra-fine pleated material that captures sand, gravel, leaves, and even microscopic debris. In real-world use, these filters dramatically improve water clarity compared to standard mesh filters. The numbered panels (1-4) simplify installation: remove in order and replace in reverse, so even first-time users can swap them in minutes. The filters are also washable with a garden hose, retaining their shape and effectiveness after repeated cleanings.
Build quality is reassuringly sturdy. The pleated material holds up well under water pressure and regular cleaning. Each panel measures 9 x 8 x 2.1 inches and weighs just over a pound, making them lightweight yet durable. The white color blends inconspicuously into most pool cleaner baskets. Compatibility is extensive, covering over 25 Dolphin and Maytronics models, which adds significant value for households with multiple cleaners or future upgrades.
One potential drawback is that the ultra-fine mesh may clog faster than coarser filters, especially in heavily debris-laden pools. This means more frequent cleaning sessions, but the ease of rinsing offsets this inconvenience. Additionally, while compatibility is broad, it is not universal, so buyers should verify their specific model before ordering. The initial fit on some cleaner baskets might feel snug, but this ensures a secure seal.
Overall, the Henkgo ultra-fine filter panels offer an excellent balance of performance, durability, and affordability. They deliver professional-grade filtration at a fraction of the OEM cost. For Dolphin pool cleaner owners seeking clearer water and less maintenance, these filters are a smart investment. The simple installation and reusable design make them a practical choice for any pool season.
Pros
- Microfiltration prevents clogging and maintains strong suction for thorough cleaning
- Sturdy ABS construction ensures durability even in heavy-duty use
- Wide compatibility saves hassle of finding exact match for various Dolphin models
- Simple maintenance with periodic rinsing; no tools required
- Cost-effective alternative to OEM parts with comparable performance
Cons
- May require more frequent rinsing if the pool is heavily soiled or has fine debris
- Only one basket included; some pool owners may need to purchase additional for larger pools
- Not compatible with all Dolphin models; verify compatibility list before purchase
The Fiitzn Ultra Fine Filtration Basket is a replacement filter designed for a wide range of Dolphin robotic pool cleaners, including models like the S50, Active 15, Echo, Nautilus CC, Encore, E10, E20, Proteus DX3, Solo, and Advantage. This part (9991460-R1) is ideal for pool owners seeking an affordable, high-performance alternative to the original filter. It is especially suited for those who want to improve water clarity by trapping fine particles without sacrificing cleaning efficiency.
The standout feature of this basket is its microfiltration technology, which captures small debris while allowing larger particles to pass through. This design prevents the filter from clogging quickly, ensuring consistent suction and longer cleaning cycles. In real-world use, this means less downtime for rinsing and more effective pool maintenance, even in dirty conditions. The basket maintains strong performance over weeks of use before needing a quick rinse.
Build quality is solid thanks to the ABS plastic frame, which resists cracking and deformation under pressure. The filter layer is securely supported, reducing the risk of tearing during operation. Installation is straightforward: it fits exactly like the original part, so no modifications or adapters are needed. Rinsing every 4-6 weeks keeps it working optimally, and with proper care, the basket can last 2-3 years, offering excellent value.
One potential drawback is that in extremely dirty pools, the filter may need more frequent rinsing to maintain flow. Additionally, the package includes only one basket, so owners of larger pools might need to buy a second. Also, while compatibility is broad, it does not cover every Dolphin model, so double-checking the list is wise. These are minor trade-offs for the price and performance.
Overall, the Fiitzn Ultra Fine Filtration Basket delivers on its promise of efficient fine debris capture and durability. It is a smart upgrade or replacement for Dolphin pool cleaner owners who want to keep their water crystal clear without breaking the bank. The combination of microfiltration, sturdy construction, and broad compatibility makes it a reliable choice for routine pool care.
Dimensions: 9.1 x 7.1 x 5.3 inches
Weight: 1 pound
Material: ABS plastic frame with microfiltration mesh
Compatibility: Dolphin models S50, S100, Active 15, Echo, T15, Proteus DX3, E20, Cayman, Escape, Nautilus CC, Encore, E10, Solo, Advantage
Replaces OEM Part: Maytronics 9991460-R1
Maintenance: Rinse every 4-6 weeks; expected lifespan 2-3 years with proper care
Pros
- Superior filtration from ultra fine pleated material, outperforming standard non-pleated filters.
- Durable ABS frame withstands regular use and chemical exposure without cracking.
- Cost-effective 4-pack reduces per-cartridge cost and frequency of replacement.
- Easy to clean and reuse, extending the life of each filter panel.
- Backed by a 1-year warranty for added confidence.
Cons
- Not compatible with older Nautilus CC, Nautilus (original), or Triton models; verify your robot before ordering.
- Some users may find the initial fit slightly snug in certain robot models, though it settles over time.
- Pleated filters may require more frequent rinsing in heavy-debris pools compared to coarse mesh options.
The SUNRRA Ultra Fine Filters are a versatile replacement option for a wide range of Dolphin robotic pool cleaners, including the Nautilus CC Plus, CC Supreme, M200, M400, M500, and many others. If you own one of these popular Maytronics models and want to improve water clarity, this 4-pack of pleated cartridges is a smart upgrade.
What sets these filters apart is their ultra fine pleated construction. Unlike standard non-pleated cartridges that let fine sediment slip through, the dense pleats trap even tiny particles like algae, pollen, and dust. The result is noticeably clearer pool water and a cleaner floor after each cycle. In real-world use, the filtration performance is excellent, especially for pools that struggle with cloudy water.
The build quality is solid: the frame is made from heavy-duty ABS plastic that resists cracking and tearing, even after repeated rinsing and seasonal storage. SUNRRA claims a lifespan of 2-3 years, which is reasonable if you clean them every 4-6 weeks. The 4-pack also means you have spares on hand, saving you from last-minute replacements.
One important note: these filters are not compatible with the original Nautilus CC, older Nautilus, or Triton series models. Always double-check your robot's model number before purchasing. Also, because the pleats are so fine, they may clog faster in pools with heavy leaf debris; you may need to rinse them more often than coarse mesh filters.
Overall, the SUNRRA Ultra Fine Filters offer excellent value for Dolphin owners who want premium filtration without paying premium prices. The 1-year warranty adds peace of mind, and the 4-pack ensures you're set for multiple seasons. If your robot is compatible, this is a highly recommended upgrade for crystal-clear pool water.
Pros
- Designed to replace Maytronics 9991432-R4 for many Dolphin robotic cleaner models
- Ultra fine pleated media traps both small particles and larger debris effectively
- Reinforced ABS frame keeps the filter stable during operation
- 4 pack provides good value and a longer interval before you need to reorder
- Simple maintenance with periodic rinsing every 4 to 6 weeks
Cons
- Not compatible with many Dolphin models such as Nautilus CC, M600, S200, Triton PS, and others, so check fit carefully before buying
- Aftermarket part is not an original Maytronics product, which may matter to some buyers
- No customer reviews are available yet, so long-term real-world performance is less proven
The Funmit M400 Ultra Fine Cartridge Filter is a 4 pack replacement designed for the Dolphin Nautilus CC Plus and a wide range of compatible robotic pool cleaners. It replaces Maytronics part 9991432-R4, making it a practical option for pool owners who want dependable filtration without the premium price of the OEM part.
The standout feature is the ultra fine pleated filter paper, which captures sand, leaves, hair, and other debris while maximizing surface area. The heavy duty ABS plastic frame keeps the pleats stable during operation and prevents the filter from deforming under water flow, so the cleaner maintains strong suction and consistent performance.
Maintenance is straightforward: rinsing the filter every 4 to 6 weeks is enough to keep it working well, and with proper care each filter can last 2 to 3 years. The 4 pack is especially convenient for owners who clean frequently or have a large pool, because there is always a fresh filter on hand.
The main drawback is compatibility. This filter does not fit several popular Dolphin models, including Nautilus CC, M600, S200, Triton PS, and others, so it is essential to verify your pool cleaner model before purchasing. As an aftermarket part, it also does not carry the original manufacturer branding, though the build quality is solid for the price.
Overall, the Funmit M400 filter replacement offers strong filtration, durable construction, and good value for owners of compatible Dolphin robotic cleaners. If you confirm the fit first, this 4 pack is a smart, budget friendly way to keep your pool clear all season.
Color: White
Dimensions: 10.5 x 6.375 x 10.5 inches
Package includes: 4 cartridge filters
Replaces Maytronics part 9991432-R4
Compatible with Dolphin Nautilus CC Plus, M400, M500, M200, M4, M5, Wave 65, Wave 90, C3, C4, Oasis Z5i, Aquarius XL, Liberty, Odyssey, Sigma, Triton Plus (old)
Buying Guide
Filtration Micron Rating and Debris Capture
The core difference between standard and ultra-fine filters lies in micron rating. Standard Dolphin baskets typically have a mesh around 100 to 150 microns, adequate for larger debris. Ultra-fine filters, like the 50-micron mesh in the Ultra-Fine Filter Basket Part No. 9991460-R1 from Doule King, trap sand, hair, algae, and even fine silt. This means fewer passes to achieve sparkling clarity, especially in pools near trees or with heavy foot traffic.
When evaluating options, look for products that specify their micron level. The SUNRRA Ultra Fine Filters Compatible with Dolphin use pleated media that increases surface area, capturing particles standard filters miss. If you struggle with cloudy water repeatedly, an ultra-fine set with a rating of 50 microns or finer is your best bet.
Compatibility and Fitment
Not all ultra-fine filters work with every Dolphin model. Many aftermarket baskets are designed to replace part numbers 9991460-R1 or 9991467-R4, but you must verify your cleaner’s compatibility. For example, the Ulticor Ultra Fine Filter Basket Compatible fits S50, S100, Active 10/15, Echo, and many others, but explicitly states it is not compatible with Nautilus CC Pro or Supreme. Meanwhile, the M400 Ultra Fine Cartridge Filters Compatible from Kerneed are tailored for Nautilus CC Plus and M400/M500 series.
Always double-check your robot’s model number and the part number cited in the product listing. Some older Active 10 or S50 units require removing a plastic piece inside the robot for the basket to fit properly, as noted by ULTICOR. Taking a few minutes to confirm fitment saves you the hassle of returns.
Durability and Washability
Ultra-fine filters that you can rinse and reuse offer long-term savings. Most aftermarket sets are made with UV-resistant polypropylene frames and tough ABS plastic that withstand pool chemicals and sun exposure. The Replace Part#9991467-R4 Ultra-Fine Filter Panels from Henkgo, like the CLLOMAGY version, are washable and designed for 50+ cleanings if you use a garden hose sprayer.
Filters that are easy to remove and clean encourage regular maintenance. Rinsing every 4 to 6 weeks keeps them effective. Models with pleated cartridges, such as the M400 Ultra Fine Cartridge Filter Replacement from Funmit, trap dirt inside the pleats and release it easily under pressure. A durable filter can last two to three seasons, making the upgrade worthwhile.
Ease of Installation and Maintenance
Most ultra-fine filter baskets and panels snap into place without tools. For basket-style filters like the Fiitzn Ultra Fine Filtration Basket Compatible, installation is a direct swap with the original. For cartridge panel sets, numbering on each panel (1 to 4) guides replacement order, making it foolproof.
Cleaning is equally straightforward; simply pop out the filter, spray from the inside out, and reinsert. This low-maintenance routine ensures your Dolphin continues to pick up fine debris without clogging. For more tips on keeping your pool robot in top shape, explore our best pool cleaner wall climbing brush guide.
Final Thoughts
Upgrading to an ultra-fine filter is a smart move for any Dolphin owner who values crystal-clear water without extra scrubbing. If your robot uses a basket-style filter, the Ultra-Fine Filter Basket Part No. 9991460-R1 from Doule King offers the best balance of micron capture and durability for most popular models. For those with a cartridge-style system like the Nautilus CC Plus or M400 series, the SUNRRA Ultra Fine Filters Compatible with Dolphin provide consistent performance at a reasonable cost. Both choices outshine standard filters by trapping fine debris that keeps your pool inviting all season long.
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Frequently Asked Questions
What is the difference between standard and ultra-fine Dolphin filters?
Standard filters capture larger debris like leaves and twigs, typically with a mesh around 100 to 150 microns. Ultra-fine filters use a finer mesh (often 50 microns) to trap sand, algae, silt, and other microscopic particles, resulting in noticeably clearer water after each cycle.
Can I use an ultra-fine filter in my Dolphin S50 or Active 15?
Yes, many aftermarket ultra-fine baskets are compatible with S50, S100, Active 10, Active 15, and similar models. Look for products specifically listing these robots, such as the Fiitzn or Ulticor baskets. Some older units may require removing a small plastic piece inside the robot for proper fit.
How often should I clean ultra-fine Dolphin filters?
We recommend rinsing the filter every 4 to 6 weeks for optimal performance. Use a garden hose with moderate pressure, spraying from the inside out to dislodge trapped debris. Regular cleaning extends the life of your filter and keeps your robot running efficiently.
Are aftermarket ultra-fine filters as good as original Dolphin parts in 2026?
Many aftermarket options from brands like SUNRRA, Kerneed, and Funmit match or exceed OEM quality. They use durable materials and finer filtration media, often at a lower cost. Just ensure you choose a brand with positive reviews and a clear compatibility list. For more comparisons, visit our Comparisons category.
