Size grade
150-200 microns
Pack size
100 g blister
Water type
Freshwater + Marine
Protein / fat
5.9% / 1%
Delivery
Frozen, pick up in store only
Cost per gram
$0.11
Food form
Frozen cubes, blister pack
Pellet size
150 to 200 microns
Suits
Filter feeders and fish fry
Feeding guide
2 to 5 times daily
Ocean Nutrition Frozen Rotifers
Microscopic frozen rotifers sized for larvae and filter feeders. Ocean Nutrition frozen rotifers are whole Brachionus plicatilis, rinsed before flash-freezing and sized at 150–200 microns – small enough for larval fish and shrimp, and for filter feeders that can't manage larger frozen foods.
Key features
- Single ingredient – pure rotifers, nothing else added.
- Very small particle size – 150–200 microns, sized for larvae and filter feeders rather than adult fish.
- Rich in EPA and DHA – highly unsaturated fatty acids important for larval development.
- Buoyant – stays in suspension after thawing, keeping it available to filter feeders and slow-swimming larvae for longer.
- Rinsed before freezing – reduces the amount of culture water and debris going into your tank.
Ingredients
Reproduced verbatim from the manufacturer: Pure rotifers (Brachionus plicatilis).
Ocean Nutrition doesn't publish a guaranteed analysis (crude protein, fat, fibre, moisture, ash) for this product.
Specifications
| Form | Frozen, whole rotifers |
|---|---|
| Particle size | 150–200 microns |
| Pack size | 100 g blister |
| Country of manufacture | Belgium |
| Storage | Keep frozen at -18°C or below until use |
Suitable for, and not suitable for
Suitable for: marine fish and shrimp larvae, small tropical freshwater fish larvae, and filter-feeding invertebrates such as scallops, jellyfish, anemones, nudibranchs and soft corals.
Not suitable for: adult fish as a primary food – the particle size is aimed at larvae and filter feeders, and larger fish need a coarser food to feed efficiently.
Thawing and feeding
How do I thaw it?
Thaw a portion in a small amount of tank or aquarium water. Because rotifers are buoyant, gently agitate the thawed portion before dosing so it disperses through the water column rather than settling. Never refreeze thawed food.
How often should I feed it?
Feed small amounts several times a day for larvae and filter feeders, matching natural grazing patterns rather than one large feed. Remove excess to protect water quality in a larval-rearing setup.
Storage and cold chain
This is a frozen product. Transfer it to your freezer immediately on arrival and keep it at -18°C or below.
Goes well with
Rotate with our other Ocean Nutrition frozen lines, stepping up to red plankton or mysis as fry and larvae grow and can manage larger particles.
Warranty and delivery
As a perishable frozen food, this isn't covered by a manufacturer warranty the way equipment is; your rights under Australian Consumer Law still apply if a pack arrives damaged or not as described.
Frozen food is pick up only from our North Lakes store, because a pack that thaws on the way cannot be refrozen.
Common questions
What's the difference between this and live rotifer cultures?
Frozen rotifers are a convenient next-best alternative to live rotifer cultures, without the ongoing work of culturing – useful for topping up or bridging gaps in a live culture supply.
Can filter-feeding corals really eat something this small?
Yes – the 150–200 micron size is specifically aimed at filter feeders such as soft corals, anemones and jellyfish that can't manage larger frozen foods.
Will rotifers cloud my water?
Dose in small amounts and remove excess after feeding; because the product is pre-rinsed before freezing, it introduces less debris than an unrinsed live culture.
Do I need to feed rotifers if I already feed baby brine shrimp?
Rotifers suit the earliest larval stages before mouths are large enough for baby brine shrimp, so the two are typically used at different points in a rearing schedule rather than interchangeably.




