Red Sea REEFER RSK-900 Protein Skimmer

Bring powerful REEF-SPEC filtration to large reef and marine aquariums with the Red Sea REEFER RSK-900 Protein Skimmer.

Designed for large, heavily stocked systems, the RSK-900 combines a high-performance Sicce PSK-1200 pump, optimized air and water flow, an efficient diffusion chamber, precision adjustment, and flexible sump installation to provide consistent removal of dissolved organic waste.

Red Sea rates the RSK-900 for systems up to 240 gallons for SPS reefs, 500 gallons for mixed reefs, and 740 gallons for fish-only systems.

High-Performance REEF-SPEC Skimming

The RSK-900 is engineered around Red Sea's REEF-SPEC criteria, balancing water throughput, air-to-water ratio, and contact time to efficiently remove organic waste from aquarium water.

The included Sicce PSK-1200 delivers:

Air Flow: 900 LPH / 235 GPH
Water Flow: 2,000 LPH / 530 GPH

The pump, venturi, diffuser, and reaction chamber work together to create a dense mixture of fine bubbles and maximize contact with aquarium water.

Built for Large Aquariums

Red Sea rates the RSK-900 based on aquarium type and expected organic load:

SPS / High Demand Reef: Up to 240 gallons
Mixed Reef: Up to 500 gallons
Fish Only: Up to 740 gallons

That makes it an excellent choice for large reef displays, heavily stocked marine aquariums, predator systems, and other high-bioload applications.

Quiet Operation

The RSK-900 is designed to deliver serious skimming performance without turning the sump into a machine room.

Red Sea incorporates vibration-reducing components and air silencing into the design to help reduce operational noise while maintaining strong air and water movement.

Flexible Sump Installation

Three assembly configurations allow the skimmer's pump inlet and regulation valve to be repositioned to better fit different sump layouts.

This flexibility is particularly valuable in larger systems where return pumps, reactors, dosing lines, and other equipment may already occupy significant sump space.

Precision Adjustment

A precision geared regulation valve allows fine adjustment of the internal water level, helping you dial in the skimmer for the desired foam consistency and skimmate production.

The design also incorporates easy pump access and a collection cup drainage system to simplify routine maintenance.

Specifications

Model: REEFER RSK-900
Pump: Sicce PSK-1200
Air Flow: 900 LPH / 235 GPH
Water Flow: 2,000 LPH / 530 GPH
Height: 23" / 59 cm
Recommended Water Depth: 8–9" / 20–24 cm

Product Highlights

Powerful protein skimmer for large marine aquariums

Rated up to 740 gallons depending on bioload

Sicce PSK-1200 pump

900 LPH air intake

2,000 LPH water flow

REEF-SPEC performance design

Precision geared adjustment valve

Quiet operation

Three sump installation configurations

Quick-release pump access

Collection cup drainage capability

Designed for large reef and high-bioload systems

Important Model Note

This is the REEFER RSK-900 AC Protein Skimmer.

It is different from Red Sea's newer REEFER DC Skimmer 900, which adds a variable-speed DC pump, Self-Leveling functionality, ReefBeat integration, and requires a ReefRun Dual Controller.

That's worth stating clearly since you're carrying the newer DC models too.

Why Buy From Infinity and Beyond Aquatics?

Infinity and Beyond Aquatics offers premium filtration equipment for everything from nano reefs to large marine systems.

Shop protein skimmers, pumps, controllers, filtration media, lighting, dosing equipment, testing, and other reef essentials from leading aquarium brands, all in one place.