Dolphin UltraFilters Kit
Four ultra-fine UltraFilter panels and the filter base that convert a bag-filter Dolphin, such as the Nautilus Pool Up, to cartridge filtration. Run the bag on leaf days and the UltraFilters when dust, pollen and algae are clouding the water, and rinse either one with a hose.
- Genuine Maytronics part
- Part 9991412-R1
- 30-day returns
From leaf bag to ultra-fine, in the same basket.
A filter bag is built for bulk: leaves, twigs and the opening-day mess. The UltraFilters kit gives the same robot a second mode. Lift the bag out, clip the filter base and four pleated panels in, and the Dolphin starts catching the fine dust, sand, pollen and algae that make water look tired.
Does the UltraFilters kit fit my Dolphin?
One check settles it: open the lid. If the basket holds a filter bag, this kit converts it. If it holds cartridge panels or a MaxBin™, you want NanoFilters™ instead.
Dolphin Nautilus Pool Up
Ships with the high-capacity filter bag. The UltraFilters kit is its listed upgrade: swap between the bag and ultra-fine panels as the pool demands.
Nautilus Pool Up ›Basket with a bag? Likely a match.
Maytronics sells this kit as the conversion from bag filters to ultra-fine cartridges. Fit still varies by model year, so send us your robot's serial number and we will confirm before you order.
Confirm my fit ›
Max-Series™: Escape, Cayman, Quantum
MaxBin™ robots take NanoFilter™ panels or a complete NanoFilter MaxBin™ set, not this kit.
Shop NanoFilters ›
ProLine™: Premier, Sigma
Every ProLine™ robot ships with NanoFilters™ in the box; order a spare set rather than this kit.
Shop NanoFilters ›The bag cleans the floor. UltraFilters clean the water.
Leaves you can see are the easy part. The cloudiness after a windy week or a pollen bloom is thousands of particles too small for a bag's weave, and ultra-fine pleats are what pull them out.
Two filters, one season.
Bag for leaf days. Panels for everything else.
Open the season on the bag while the heavy debris comes out, then switch to the UltraFilters for the swim months. Maytronics gives the same advice for every Dolphin with two filter grades: coarse first, then ultra-fine once the bulk is gone. The base and panels lift out as one unit, so the swap takes seconds.
Which filter should I use? ›Rinse, don't scrub.
After each cycle, lift the basket, pull the panels and hose them off from the clean side out. They go back in wet. When a panel stops rinsing back to white, the pleats are packed with fine particles and it is time for a fresh set.
How to clean Dolphin filters ›Three steps, no tools.
Lift the bag out
Open the filter cover, pull the basket and remove the filter bag. Rinse the basket while you are there.
Seat the base and panels
Drop the filter base into the basket and clip the four UltraFilter panels into their channels until each one clicks.
Close and clean
Return the basket, close the lid and run a cycle. Rinse the panels afterwards and keep the bag dry for the next leaf day.
| Feature | Filter bag | UltraFilters kit |
|---|---|---|
| Built to catch | Leaves, twigs, grass, bulk debris | Dust, sand, pollen, algae |
| Water clarity | Clean floor | Clean floor and clearer water |
| Capacity | Highest | Good; rinse after each cycle |
| Use when | Season opening, heavy leaf days | Pollen, dust, algae, swim season |
| Cleaning | Empty and rinse | Hose rinse; replace when no longer white |
| Included with | Bag-filter Dolphins | Sold separately, part 9991412-R1 |
UltraFilters or NanoFilters? Match the basket, not the name.
Both are genuine Maytronics ultra-fine filtration and both rinse with a hose. The difference is the robot. The UltraFilters kit (9991412-R1) is a conversion: it brings a filter base and four pleated panels to a Dolphin that was designed around a bag, such as the Nautilus Pool Up. NanoFilters™ are panels cut for the top-load baskets on the ProLine™ and Max-Series™ robots, which already run cartridges.
If you are shopping for a robot rather than a filter, the shortest path to ultra-fine water is a lineup that ships with it: every ProLine™ Dolphin includes NanoFilters™, and the Max-Series™ Escape and Cayman take them as a one-time upgrade. Either way, replacement filters by robot are a click away when a set stops rinsing white.
Buy the Dolphin UltraFilters kit
Buy direct and it ships free from our warehouse, or pick it up from an authorized Dolphin dealer.
Buy direct from us
$99Live price, live stock
Round out the setup.
Genuine Maytronics upgrades and spares for the ProLine™ and Max-Series™ robots, all shipped free from our warehouse.
Dolphin NanoFilters
Premier, Sigma, Quantum, Escape, Cayman
From $99
Dolphin Weekly Timer Power Supply
Escape add-on · timer-equipped Dolphins
$199
Dolphin Universal Caddy
Every Dolphin robot
$145
Dolphin Premium Caddy Cover
Dolphin Universal Caddy
$99
Dolphin Classic Caddy Cover
Dolphin Universal Caddy
$79
Replacement parts by robot
Filters, brushes, tracks, cables and power supplies
Browse the parts hub ›
Dolphin UltraFilters: frequently asked questions
What is in the Dolphin UltraFilters kit?
Four ultra-fine UltraFilter panels and the filter base they clip into. Together they convert a Dolphin that ships with a filter bag to cartridge filtration. Maytronics lists it as the bag-to-ultra-fine cartridge conversion kit, part 9991412-R1.
Which Dolphin robots does the UltraFilters kit fit?
Dolphin robots that ship with a filter bag in a basket, such as the Nautilus Pool Up. If your robot already uses cartridge panels or a MaxBin, it does not need this kit; the Escape, Cayman, Quantum, Premier and Sigma take NanoFilters instead. Unsure? Send us your serial number.
Can I switch back to the filter bag?
Yes. The bag and the UltraFilter base swap in and out of the same basket, so you can run the bag on heavy-leaf days and the UltraFilters when fine debris, pollen or algae is the problem.
What do UltraFilters catch that the bag does not?
The fine particles that slip through a bag's weave: dust, sand, pollen, algae and the haze that keeps water from looking clear. The bag still wins on bulk, which is why Maytronics suggests opening the season on the coarser filter and switching to ultra-fine afterwards.
How do I clean the UltraFilters, and when do I replace them?
Lift the basket out after each cycle and rinse the panels with a garden hose; they go back in wet. When a panel no longer rinses back to white, fine particles have packed it and it is time for a new set.
Are UltraFilters the same as NanoFilters?
No. NanoFilters are the Gen-2 panels for the ProLine and Max-Series top-load baskets. The UltraFilters kit is the conversion for bag-filter Dolphins. Both are ultra-fine; they fit different robots.
Not sure the UltraFilters kit fits your Dolphin?
Send us your robot's model and serial number and we will confirm whether it takes this kit or a NanoFilter set. The kit ships free from our warehouse with 30-day returns.