Your Dolphin Nautilus CC Plus works hard all season, but even the best robotic pool cleaner needs fresh filters to keep your water sparkling. Over time, standard filter panels lose their ability to trap fine debris like sand, algae, and pollen. That is where ultra-fine replacements come in. They capture particles as small as a few microns, leaving your pool floor spotless. In this guide, we have reviewed seven top-rated ultra-fine filter options compatible with the Nautilus CC Plus and similar models. Whether you need a budget-friendly four-pack or an eight-pack for extended use, you will find a match here. For more on general replacement choices, check out our top dolphin nautilus CC replacement filters for 2026.
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: What to Look for in Ultra-Fine Filters
Compatibility with Your Dolphin Model
Not all filters fit every Dolphin model. The Nautilus CC Plus uses part number 9991432-R4, and most third-party replacements list compatible models. Always verify your cleaner model before buying. Many filters also work with the Nautilus CC Supreme, M200, M400, M500, Sigma, and others. However, they are often not compatible with the older Nautilus CC (without Plus) or Triton PS models. Double-check the product description to avoid a mismatch. For a broader look at compatible options, see our best dolphin nautilus CC ultra fine filters.
Filtration Efficiency and Pleat Design
Ultra-fine filters use dense pleated fabric to trap tiny particles. More pleats generally mean better filtration and longer life between cleanings. Look for filters made with premium microfiber or felt-like material that captures sand, silt, and even dead algae. Some brands boast “super-fine pet filter paper” which is especially effective for fine debris. Rinsing every four to six weeks keeps performance high. If you want maximum clarity, prioritize pleated designs over standard mesh panels.
Frame Durability and Build Quality
The plastic frame must withstand water pressure and repeated handling. Heavy-duty ABS plastic is the gold standard, as it resists cracking and warping. Some cheaper filters use thinner plastic that can break during installation or cleaning. A sturdy frame also helps the filter hold its shape, ensuring even water flow and preventing debris from bypassing the media. Check customer feedback for mentions of frame breakage, and choose brands that emphasize reinforced edges.
Pack Size and Value
Ultra-fine filters come in packs of four or eight. An eight-pack costs more upfront but saves money per filter and means fewer reorders. If you have a large pool or run your cleaner daily, an eight-pack is a smart investment. For smaller pools or occasional use, a four-pack may be sufficient. Some brands also offer multi-packs with a mix of fine and ultra-fine panels, giving you flexibility. Consider your cleaning frequency and how often you replace filters when deciding. For more insights on fine filter replacements, read our best dolphin nautilus CC fine filter replacements for 2026.
Final Thoughts
Choosing the right ultra-fine filter for your Dolphin Nautilus CC Plus comes down to your budget and cleaning needs. If you want a reliable four-pack at a great price, the Poolzilla Pool Cleaner Ultra-Fine Filters offer excellent build quality and high customer satisfaction. For those who prefer bulk value and long-term savings, the SUNRRA Ultra Fine Filters Compatible with Dolphin eight-pack delivers consistent performance and a sturdy ABS frame. Both options are washable, reusable, and compatible with your cleaner, so you can enjoy a pristine pool all season.
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Frequently Asked Questions
Are Dolphin Nautilus CC Plus ultra-fine filters washable?
Yes, most ultra-fine filters are designed to be rinsed with a garden hose. Simply remove the filter panels and spray off debris. For best results, let them air dry completely before reinstalling. Avoid using a pressure washer, as it can damage the pleated fabric. Regular washing extends the life of the filters to two or three years.
How often should I replace the ultra-fine filters in my Nautilus CC Plus?
With proper rinsing every four to six weeks, a set of ultra-fine filters can last two to three seasons. Replace them when you notice reduced water flow, visible wear on the pleats, or if the filter no longer rinses clean. If you run your pool cleaner daily, you may need to swap filters more frequently. For a detailed guide on replacement cycles, see our best dolphin nautilus CC replacement filters.
Will these filters work with the older Dolphin Nautilus CC (non-Plus)?
No, most ultra-fine filters labeled for the Nautilus CC Plus are not compatible with the original Nautilus CC. The dimensions and mounting system differ. Always check the product description for explicit compatibility. Many brands clearly state “Not for Nautilus CC” to avoid confusion. If you have the older model, look for filters specifically designed for that version.
Can I use ultra-fine filters with other Dolphin models like the M400 or Sigma?
Yes, many ultra-fine filters that fit the Nautilus CC Plus also work with the Dolphin M200, M400, M500, Sigma, Odyssey, and several others. They all share the same part number 9991432-R4. However, always confirm compatibility before purchasing, especially for newer models like the Nautilus CC Supreme. The product listings typically list all supported models.
