Dolphin replacement bottom lid assembly for robotic pool cleaners — Part 99919116, snaps-in seal & filter support

The Dolphin Genuine Replacement Bottom Lid Assembly (Part 99919116) is the original equipment cover for the filter compartment that restores proper sealing and filter support on compatible Dolphin robotic pool cleaners.

When a worn or cracked bottom lid reduces suction or lets debris bypass the filter, replacing it with an authentic Dolphin part brings the cleaner back to designed performance. Part 99919116 snaps into the base of the robot and secures the micro filter bag so debris stays contained, helping your unit run efficiently season after season.

Which Dolphin models will this bottom lid assembly work with?

This bottom lid assembly is compatible with a broad range of legacy and current Dolphin cleaners, but not every model. It fits many Advantage Plus, Apollo, Atlantis, Deluxe, DX series, H50, Nautilus (original), Neptune, Primal, and Saturn variants, while being incompatible with some Advantage lineup and Nautilus CC or Proteus DX models.

• Compatible includes: Advantage Plus, Apollo, Apollo Plus, Atlantis, Deluxe 3/4, DX3/DX3S/DX4/DX4S, H50, Nautilus (old), Neptune/Neptune Plus, Primal, Saturn.
• Not compatible with: Advantage, Advantage Pro, Advantage Ultra, Nautilus CC/CC Plus/CC Supreme, Proteus DX3/DX4.
• Check your unit's parts diagram or model plate to confirm fit before ordering.

How does installing this bottom lid improve cleaning performance?

Replacing a damaged or missing bottom lid restores the filter compartment’s seal and holds the micro filter bag correctly in place. That prevents fine debris from escaping back into the pool and keeps the motor working under proper load, which improves pickup and overall efficiency.

• Re-establishes a tight seal around the filter area to prevent bypassed debris.
• Secures the Micro Filter Bag 99954307-R1 (sold separately) for reliable containment.
• Reduces strain on the robot’s drive and pump by restoring correct suction dynamics.

Is this part easy to install and maintain?

Yes — the bottom lid assembly is engineered for quick, tool-free replacement and durable service life. Most owners can swap the part in seconds by opening the robot’s access area and snapping the new lid into place; routine checks keep it performing well.

• Tool-free snap-in installation designed for fast replacement.
• Durable molded materials resist pool chemicals and sun exposure.
• Inspect periodically for cracks or worn latching surfaces; replace if damaged.

What accessories or extra parts should I consider with this replacement?

While the bottom lid brings the housing back to spec, pairing it with a fresh micro filter bag and inspecting other wear parts ensures full restoration. Micro Filter Bag 99954307-R1 is recommended to capture fine debris; also check tracks, brushes, and seals for wear while you have the unit open.

• Recommended: Micro Filter Bag 99954307-R1 (not included) for optimal debris capture.
• Inspect brush strips, tracks, and O-rings and replace if showing wear.
• Keeping spare genuine parts on hand reduces downtime during pool season.

Who is this for? Pool owners and service technicians who use compatible Dolphin robotic cleaners and need an authentic replacement bottom lid to restore proper filter placement and sealing. If your cleaner’s filter area is cracked, warped, or failing to hold the micro filter bag securely, this genuine Dolphin part 99919116 is a direct-fit option to return reliable cleaning performance without improvising with non-OEM components.