
Genuine Maytronics part · Filters
Dolphin Bottom Lid With Ultra-Fine Filters
Part number 9991412-R1 · UPC 810071221019 · 1 year part warranty
Genuine Maytronics bottom lid with ultra-fine filters for converting the Dolphin W20 from bag filtration to cartridge filtration.
$139.99 MSRP
Not stocked by Poolbots. Sold on Amazon as a genuine Maytronics part.
Ships from Amazon.com. As an Amazon Associate, Poolbots earns from qualifying purchases.
About this part
What it does and when to replace it.
This genuine Maytronics bottom lid with ultra-fine filters lets you change your Dolphin W20 from bag filtration to cartridge filtration. It replaces the bag-filter setup with a cartridge-filter option.
Dolphin W20 is the only model on the confirmed compatibility list for part 9991412-R1. Pack quantity is not specified. Poolbots does not currently stock this part. Contact Poolbots' pool experts by live chat or phone for help identifying it and checking fit.
- Use part number 9991412-R1 when asking Poolbots' pool experts to help identify this part.
- Do not assume fit from the additional names on the spec sheet. Dolphin W20 is the only confirmed compatible robot.
Compatibility
Fits these Dolphin robots.
Confirmed by Maytronics' compatibility checker and each robot's own spare-parts list.
Also listed by Maytronics for: Dolphin W20, POOL IN, POOL UP, Dolphin POOL UP, Dolphin Swift, Dolphin X FORCE 10, M200, Dolphin M200, Dolphin DX3, Dolphin Swell, Cosmos 20, Dolphin X FORCE 20, Dolphin Cosmos 30, Dolphin DX5, Dolphin XT3, W20.
Do it yourself
How to replace it at home.
Switch off and unplug the power supply.
Remove the robot from the pool and let it drain.
Follow the Dolphin W20 instructions to remove the existing bottom lid and filter setup.
Install the replacement bottom lid and ultra-fine filters according to the model's instructions.
Check that the lid is secure before returning the robot to the pool.
Maytronics' video for this part
Step-by-step answers for this kind of part
How do I replace the filter panels on my Dolphin robot?Video15 min
Find your model below, then follow its video and instructions. The panel removal and installation steps vary by filter design.
S50 (Cayman, T15, T25, Active 10, Escape, Encore, E20, E25) & S100 (Advantage, Proteus DX3, Saturn, Echo, Nautilus CC, Active 15, Escape, Liberty 200/300/400)

Step 1Remove the old filter panels
- Lift the filter cover open.
- Take the filter basket out of the robot.
- Press the plastic release at the top of the filter's wide side, then lift out the released panel. The narrow side panels come out easily. The front and back panels are secured with screws, so use a Phillips-head screwdriver to release them.
- Follow the same process for the opposite side panel.
Step 2Install the replacement panels
- Slide a replacement panel into the basket.
- Push the panel against the frame until it clicks into place.
- Fit the other side panel the same way.
- With both panels in position, clip the filter's bottom section back into place.
S200 (E30, Advantage Ultra, Active 20, Quantum, T30, Proteus DX4, Triton PS) / S300 (E35/E35i, Proteus DX5i, Active 30, T35/T45, Premium 40, Explorer E30, E40i, Active 30i, T55i) / S400 (E50i, Active 50, Explorer E50) / Liberty 600

Step 1Remove the old filter panels
- Lift the filter cover open.
- Take the filter basket out of the robot.
- Press the plastic release at the top of the filter's side, then lift out the panel that releases.
- Work through the remaining narrow and wide panels using the same method.
Step 2Install the replacement panels
- Set the bottom edge of a replacement panel into the filter's lower rail.
- Push the panel into the frame so it clips into the filter.
- Press it against the frame until you hear it click.
- Fit each remaining narrow and wide panel the same way.
Premier/Dx4 (Bag filter)

Filter bag setup for Dolphin Premier
- Turn the robot upside down so you can reach the filter area.
- Release the clips underneath the filter assembly.
- Lift the assembly out of the robot.
- If the white filter screen is not already fitted, secure it with the two screws.
- Check that the filter bag sits securely on the assembly's guard rails.
- Put the filter bag assembly back in, following the guide and video.
Filter cartridge assembly setup for Dolphin Premier
- Turn the robot upside down so you can reach the filter area.
- Release the clips underneath the filter assembly.
- Lift the assembly out of the robot.
- Make sure the white filter screen is not installed for this setup.
- Follow the guide and video to reinstall the assembly.
- Fasten the clips underneath the assembly to secure it.
M250 (Dx3, Nautilus CC Plus)

Step 1Prepare the filter cartridges
- Lift the filter covers and take the cartridges out of the robot.
- Release the clips at the top of each cartridge.
- Inspect the non-return flap for debris.
- Check that the frame is clean before fitting replacement panels.
Step 2Fit the replacement panels
- Seat the locating tabs along the bottom of each panel in the matching grooves on the base frame.
M400/M500 (Sigma, Nautilus CC Supreme, Aquarius XL, Oasis)

Step 1Prepare the filter cartridges
- Lift the filter covers and take the cartridges out of the robot.
- Release the clips at the top of each cartridge.
- Inspect the non-return flap for debris.
- Check that the frame is clean before fitting replacement panels.
Step 2Fit the replacement panels
- Seat the locating tabs along the bottom of each panel in the matching grooves on the base frame.
M600/M700 (Active 60, E60i, Premium 60, Explorer E70)

Step 1Remove the old filter panels
- Lift the filter cover open.
- Take the filter basket out of the robot.
- Press the plastic release at the top of the filter's side, then lift out the panel that releases.
- Work through the remaining narrow and wide panels using the same method.
Step 2Install the replacement panels
- Set the bottom edge of a replacement panel into the filter's lower rail.
- Push the panel into the frame so it clips into the filter.
- Press it against the frame until you hear it click.
- Fit each remaining narrow and wide panel the same way.
Replacement panels and filter care
You can purchase replacement filter panels from Poolbots. Before ordering, confirm that the panel part number matches your robot. For help choosing the correct panels, contact Poolbots' pool experts by live chat or phone.
Additional references:
Specifications
Size & Dimension
- Package Dimensions
- 12.6x9.5x6.3 inch
- Gross Weight
- 1.94 lb
General Info
- Warranty (years)
- 1
- UPC
- 810071221019
Questions
Dolphin Bottom Lid With Ultra-Fine Filters, answered.
Which robot is confirmed to fit part 9991412-R1?
Dolphin W20 is the only confirmed compatible robot. The Maytronics spec sheet includes other model names, but their fit is not confirmed here. Ask Poolbots' pool experts by live chat or phone before choosing it for another model.
Can I buy this part from Poolbots?
Poolbots does not currently stock 9991412-R1 in its own store. This page helps you identify the part. Contact Poolbots' pool experts by live chat or phone for identification and fit help.
What warranty is listed for this part?
The listed part warranty is 1 year.












