Red Sea RSK 300 — REEFER Skimmer Sicce PSK-600 Mixed Reef 160 gal - Red Sea

The Red Sea RSK 300 REEFER Skimmer protein skimmer is the entry-level model in the REEFER Skimmer range, designed for reef aquariums up to 300 liters (80 gallons) with a heavy SPS load and up to 600 liters (160 gallons) with a mixed reef. Equipped with the Sicce PSK-600 needle-wheel pump with an oversized venturi, it produces a finely dispersed air-water mixture through a high-performance reaction chamber that maintains an ORP (REDOX) level above 350 mV — a level normally associated with ozone treatment, without ozone.

Video — Red Sea REEFER Skimmer

Capacity based on biological load

The "300" in RSK 300 refers to the liter capacity for a heavily loaded SPS aquarium. The actual capacity varies depending on your reef type:

• SPS / Heavy load: Up to 300 L (80 gal) — Acropora, Montipora, frequent feeding
• Mixed reef / Medium load: Up to 600 L (160 gal) — SPS, LPS, soft corals combined
• Fish only / Light load: Up to 900 L (240 gal) — Fish-only aquarium with few corals

Why the RSK 300 stands out from the competition

Red Sea didn't just put a pump in a conical tube. Every detail of the RSK 300 has been designed to address the irritants that reef keepers are familiar with in other skimmers:

Noise reduction — Concrete efforts

Red Sea has integrated several elements to reduce operating noise: an oversized air intake silencer on the venturi inlet, anti-vibration rubber feet, and vibration-absorbing connectors between each component. The noise level varies depending on the installation (sump type, surface under the skimmer, cabinet resonance). For reef keepers who want to go even further in silence, upgrading to the DC pump (sold separately) offers significantly smoother operation.

FoamView window and integrated neck cleaner

The RSK 300's collection cup incorporates two innovations that change daily maintenance. The FoamView window allows you to see the foam rise in the neck without removing the cup. The neck cleaner integrated into the lid is a rotating bar with a double-sided thick rubber scraper that removes accumulation on the neck walls in a few rotations. With the drainage port and its 1-meter hose with valve, you can empty the cup into an external container without ever removing it.

Hydrodynamic diffusion chamber

The diffusion plate at the bottom of the reaction chamber has numerous and prominent outlet holes that uniformly disperse the fine bubbles created by the PSK pump throughout the cone. Unlike flat diffusers from the competition, this design does not reduce either air or water flow, maximizing air-water contact time for optimal organic waste and protein extraction.

Assembly and maintenance designed for reef keepers

Red Sea uses custom short-threaded nylon screws — just a few turns to screw them in, and the wide thread prevents salt particles from getting stuck. The Sicce PSK-600 pump can be removed with one click thanks to the click-in/out bracket for quick cleaning. The cup locks into the neck with a watertight snap compression. The pump's cable routing neatly routes into the bracket without dragging in the sump water.

3 orientation options

The symmetrical base of the conical body can be installed in 3 different orientations to position the pump's water intake and the adjustment valve wherever you want in your sump. Whether your sump is narrow with access from the left, right, or front, there is an optimal configuration.

Designed for the Red Sea REEFER ecosystem

The RSK 300 integrates perfectly into the skimming chamber of Red Sea REEFER systems. The water level indicator on the skimmer regulator corresponds exactly to the water level inside the REEFER sump — everything is calibrated to work together. Compatible with REEFER 170, REEFER 250, and REEFER 350 (G1, G2, and G2+) models. Also works in any third-party sump with a water height of 15 to 20 cm (6 to 8 inches).

Technical Specifications

• Model: RSK-300
• Pump: Sicce PSK-600 needle-wheel (AC)
• Power Consumption: 22W
• Air Flow: 500 L/h (130 GPH)
• Water Flow: 1,000 L/h (265 GPH)
• Maintained ORP: 350+ mV
• Height: 53 cm (21 in)
• Footprint: 23 x 21 cm or 25 x 18 cm depending on chosen orientation
• Recommended water height: 15 to 20 cm (6 to 8 in)
• Foam regulator: Notched precision valve controlling water level in the reaction chamber
• Materials: Transparent acrylic, saltwater resistant components

Box Contents

• 1 x RSK 300 skimmer body with conical reaction chamber
• 1 x Sicce PSK-600 pump with click-in/out bracket
• 1 x Collection cup with FoamView window and integrated neck cleaner
• 1 x Oversized air intake silencer with supply hose
• 1 x 1-meter drainage hose with valve
• Assembly base with 3 orientation options
• Short-threaded nylon screws and hardware
• User Manual

DC upgrade available

The RSK 300 can be upgraded with the Red Sea REEFER DC Skimmer pump, which replaces the original Sicce PSK-600 AC pump. The DC pump offers significantly smoother operation, reduced consumption (20W), variable flow controlled via the ReefBeat app, and Self-Leveling functionality that automatically adjusts skimming intensity to prevent foam overflows. The ReefRun Dual controller is required (sold separately).

Why choose ReefSolution

Authorized Red Sea dealer in Canada with technical support in French. Complementary products available: Red Sea REEFER DC Skimmer Pump — DC upgrade pump with ReefBeat control and Self-Leveling, Red Sea RSK 600 REEFER Skimmer — Higher model for mixed reefs up to 1,200 L, Red Sea ReefMat — Automated mechanical filtration for REEFER sumps, Red Sea Coral Pro Salt — Reef salt formulated for REEFER systems. Delivery throughout Canada.

Frequently Asked Questions

Is the RSK 300 powerful enough for a REEFER 250 or a 120-gallon aquarium?

Yes. The RSK 300 is recommended by Red Sea for mixed reefs up to 160 gallons (600 liters). For a REEFER 250 (65 gallons) or a 120-gallon aquarium with an average biological load, the RSK 300 offers more than sufficient skimming performance. For a 120-gallon aquarium dominated by SPS with frequent feeding, consider the RSK 600.

Is the RSK 300 noisy?

Red Sea has integrated an oversized air silencer, anti-vibration feet, and rubber connectors to reduce noise. However, like any skimmer with an AC pump, the noise level depends on your installation: the type of sump, the surface under the skimmer, and the cabinet resonance influence the result. If silence is an absolute priority, upgrading to the Red Sea DC pump is highly recommended — it offers significantly smoother operation than the original AC pump.

How to adjust the RSK 300 skimmer?

The Sicce PSK-600 AC pump operates at a fixed speed. Skimming adjustment is done via the notched precision valve that controls the water level inside the reaction chamber. By raising the water level, the foam is pushed higher into the neck for wetter skimming. By lowering the level, the foam rises less for drier skimming. During break-in (first 1-2 weeks), set the valve for a lower water level to allow the skimmer to stabilize. After break-in, gradually raise the level to obtain a dense and stable foam in the neck. Use the FoamView window to monitor without touching the cup.

Can I upgrade the AC pump to the DC pump later?

Yes. The Red Sea REEFER DC Skimmer pump is a direct replacement for the PSK-600 AC pump. It connects to the ReefRun Dual controller (sold separately) and offers variable flow, automatic Self-Leveling function, and integration with the ReefBeat app for remote control.