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How a Protein Skimmer Works in RAS

1. Basic Principle

Protein skimmers use fine air bubbles to attract and remove:

Dissolved organic wastes (proteins, fats, fish mucus, uneaten feed).

Fine particulate matter (before it decomposes).

Some bacteria and pathogens.

2. Step-by-Step Process

Water & Air Mixing: Water enters the skimmer and mixes with micro bubbles (generated by a venturi, air stone, or needle wheel pump).

Adsorption of Organics: Organic molecules (hydrophobic) stick to the air-water interface of the bubbles。

Foam Formation: The bubbles rise, creating foam loaded with waste.

Waste Removal: Foam overflows into a collection cup, where it is removed from the system.

Why Use a Protein Skimmer in RAS

✅ Reduces organic load before biofilter (extends biofilter life).
✅ Improves water clarity (removes yellowing tannins and fine particles).
✅ Lowers disease risk (removes bacteria and pathogens).
✅ Enhances oxygen levels (from aeration).

Works best in saltwater (freshwater needs additives to improve skimming).

Not a substitute for biofiltration (does not remove ammonia/nitrite).

Optimizing Protein Skimmer Performance

Adjust bubble density (wet foam vs. dry foam).

Clean collection cup regularly (prevents overflow).

Position skimmer before biofilter (to reduce organic load).

Use ozone (O₃) injection (increases skimming efficiency).

Protein Skimmer (10-200m3/h)for RAS

Mandatory for marine RAS (shrimp, seabass, etc.).

Useful in high-density freshwater RAS (tilapia, trout) if organic load is high.