Tunze DOC Skimmer 9430 DC

Tunze DOC Skimmer 9430 DC is designed for efficient protein skimming in large marine and reef aquariums. It removes dissolved organic compounds before they break down into nitrate and phosphate. Intensive mixing of air and water also supports gas exchange and aquarium oxygenation.

The skimmer is designed for installation inside a sump. High performance is combined with relatively compact dimensions, making it suitable for aquarium cabinets. The installation must provide enough space for the 490 mm total height and at least 71 mm of additional clearance for removing the collection cup.

The DC-controlled Hydrofoamer allows the output to be adjusted according to aquarium volume, biological load, and the preferred skimming style. Water flow is adjustable up to 2,500 l/h, while air performance reaches up to 1,800 l/h.

Effective nutrient control

Marine aquariums constantly accumulate organic compounds from fish waste, uneaten food, coral mucus, and decomposing material. DOC Skimmer 9430 DC produces large quantities of fine air bubbles. Organic compounds attach to the bubble surfaces and are transported into the foam reactor and collection cup.

Removing organic material before decomposition helps limit the formation of nitrate and phosphate. Effective skimming supports clear water and stable conditions for marine fish and corals. Protein skimming does not replace regular water changes or water testing.

Adjustable DC performance

Maximum power consumption is approximately 38 W. The Turbelle Controller allows pump performance to be matched to the aquarium. This makes it easier to adjust the skimmer during initial operation and after changes in feeding or livestock.

Lower output may be suitable for lightly stocked aquariums or excessively wet skimming. Higher output can be used when fish load, feeding, and organic waste increase.

Anti-Overfoaming System

The patented Anti-Overfoaming System responds to excessive foam production caused by changes in water surface tension. Water conditioners, coral adhesives, additives, new filtration media, and contaminants may temporarily increase foam production.

If foaming becomes excessive, the system automatically reduces skimming activity. Normal operation resumes after aquarium conditions stabilize. This reduces the risk of the collection cup overflowing.

Large removable collection cup

The two-litre collection cup provides generous capacity for a high-performance skimmer. The cup also contains the foam reactor and can be removed for cleaning.

Regular cleaning maintains skimming efficiency. Organic deposits inside the cup neck gradually restrict the smooth movement of foam and should be removed before a thick layer develops.

Removable post-filter

A removable post-filter uses 300 µm nylon mesh to capture fine particles and complete mechanical filtration. The chamber can also hold compatible filter media such as activated carbon or phosphate absorber.

Filter media must not restrict water flow. The post-filter should be cleaned regularly to prevent trapped material from becoming a nutrient source.

Stable foam and reduced microbubbles

An internal mixing cylinder stabilizes foam movement inside the skimmer body and helps produce bubble-free outlet water. The stable base reduces water velocity in the lower section and supports efficient separation of air bubbles.

A limited number of microbubbles may appear during the initial running period. This normally decreases after a natural biofilm develops and the skimmer is adjusted correctly.

Aquarium recommendations

The appropriate aquarium size depends on coral sensitivity, fish population, feeding, and additional nutrient-control methods.

• Soft coral, leather coral, and anemone aquariums: up to approximately 3,500 litres
• LPS and mixed reef aquariums: up to approximately 2,800 litres
• SPS-dominated reef aquariums: up to approximately 2,000 litres

For heavily stocked SPS aquariums, select the skimmer conservatively. A high fish load and intensive feeding may substantially reduce the practical aquarium recommendation.

Key features

• High-performance protein skimmer for large marine aquariums
• Suitable for SPS, LPS, soft coral, and mixed reef systems
• Adjustable DC Hydrofoamer pump
• Water flow up to 2,500 l/h
• Air performance up to 1,800 l/h
• Maximum power consumption of approximately 38 W
• Turbelle Controller
• Patented Anti-Overfoaming System
• Automatic protection against excessive foam production
• Two-litre collection cup
• Removable foam reactor and collection cup
• Removable 300 µm post-filter
• Post-filter can hold compatible filtration media
• Internal mixing cylinder stabilizes foam
• Designed to reduce microbubbles
• Designed for sump installation
• Supplied ready to install with cleaning accessories

Technical information

• Product number: 9430.001
• Recommended aquarium size: up to 3,500 l
• Recommended for LPS and mixed reefs: up to approximately 2,800 l
• Recommended for SPS reefs: up to approximately 2,000 l
• Water flow: adjustable up to 2,500 l/h
• Air performance: adjustable up to 1,800 l/h
• Power consumption: up to approximately 38 W
• Power supply: 100–240 V / 50–60 Hz
• Recommended immersion depth: 100–200 mm
• Collection cup volume: 2 l
• Dimensions: 350 × 300 × 490 mm
• Collection cup dimensions: diameter 215 mm × height 218 mm
• Required clearance for cup removal: at least 71 mm
• Cable length to Turbelle Controller: 3 m
• Post-filter mesh size: 300 µm

Installation and setup

1. Provide at least 350 × 300 mm of free sump floor space.
2. Leave at least 71 mm of clearance above the skimmer.
3. Install the skimmer in a chamber with a stable water level.
4. Set the immersion depth between 100 and 200 mm.
5. Make sure the skimmer stands level and securely.
6. Install the post-filter and components according to the instructions.
7. Position the power supply and controller in a dry location.
8. Create a drip loop in the power cable.
9. Begin operation at moderate output.
10. Increase the pump output gradually.
11. Monitor collection cup filling during the first days.
12. Clean the collection cup, foam reactor, and post-filter regularly.
13. Maintain the Hydrofoamer pump according to the manufacturer’s schedule.
14. Disconnect the equipment before maintenance or placing hands in the sump.