Seachem Reef Zooplankton 250 mL and 500 mL — Concentrated Liquid Zooplankton for LPS and SPS Corals

Seachem Reef Zooplankton is a concentrated liquid zooplankton made of microscopic animal prey (particle size 12.5 to 500 µm), formulated to feed LPS corals, SPS corals and other carnivorous organisms in marine reef aquariums. Where phytoplankton passively feeds filter feeders, zooplankton replicates the prey corals actively hunt in nature — protein-rich particles loaded with essential fatty acids, directly usable by polyps on contact with seawater.

Available in 250 mL and 500 mL — pick your size right on this page.

Three Animal Prey Sources

Reef Zooplankton contains a blend of:

• Artemia (brine shrimp): nauplius crustaceans very rich in protein and fatty acids — a natural prey universally consumed by large-polyp LPS and SPS corals
• Rotifers: very small micro-organisms (50–200 µm) — accessible to fine-polyp SPS corals and young specimens unable to capture larger prey
• Euphausia Pacifica (Pacific krill): a crustacean rich in omega-3 oils, astaxanthin and phospholipids — reinforces coloration and delivers high caloric density to support fast growth of calcifying tissue

The formula is enriched with astaxanthin — an antioxidant carotenoid that intensifies corals' natural pigments — and ascorbic acid for product stabilization.

Who Benefits from Reef Zooplankton

• LPS corals: favia, blastomussa, lobophyllia, trachyphyllia, goniopora — their large polyps actively capture zooplankton particles in the water column
• SPS corals: acropora, montipora, pocillopora — the small rotifers are directly accessible to their tiny polyps
• Anemones and corallimorphs: discosoma, rhodactis — active consumers of animal prey
• Mixed reefs: the ideal complement to a phytoplankton to cover the reef's full feeding spectrum

Seachem's Official Feeding Protocol

• Shake well before each use — the product is particulate and settles to the bottom
• Official dose: 5 mL (1 cap) for every 190 L (50 US gallons) of water, twice weekly or as required to maintain coral growth
• Method: dose directly into the aquarium in an area of strong flow — Seachem states do not target feed: the product is intended for blanket feeding only, and a direct jet can stress sensitive coral tissue
• Storage: refrigeration after opening is recommended by Seachem but not required — the product contains preserving agents

Zooplankton + Phytoplankton — The Ideal Pairing

In a natural reef, plankton is a constant mix of plant and animal particles. Alternating a phytoplankton like Phyto-Feast (soft corals, filter feeders) with Reef Zooplankton (LPS, SPS, carnivores) replicates that diversity and covers the whole reef's nutritional needs. For fast-growing corals, Reef-Roids round out the duo as a concentrated plankton food.

How Long Each Size Lasts

• 500 mL: 100 doses of 5 mL — on a 190 L tank at the official 2x/week rate, close to a year of feeding
• 250 mL: 50 doses — about 6 months at the same rate, the trial or nano size

Frequently asked questions

What is the official Reef Zooplankton dose?

Seachem states 5 mL (the cap holds exactly 5 mL) for every 190 L (50 US gallons) of water, twice weekly or as required to maintain coral growth.

Does Reef Zooplankton need refrigeration?

Seachem recommends refrigeration after opening, but it is not required: the product contains preserving agents that keep it stable at room temperature.

Can I spot feed corals with this product?

No — Seachem explicitly states the product is intended for blanket feeding only: disperse it into the flow rather than aiming at corals, as a direct jet can stress sensitive coral tissue.