• 2 to 3 mm whole animals - flash frozen rather than minced, so the shell and the gut contents arrive intact.
• Single-ingredient declaration - Ocean Nutrition names daphnia and nothing else. No binder, no gelling agent, no added colour, no preservative.
• Hard shell provides roughage - Ocean Nutrition states the shell facilitates digestion, which is why daphnia is the long-standing answer for a bloated fancy goldfish or betta.
• High carotene content - brings out natural reds and oranges without an added colourant in the declaration.
• 96% moisture, whole-animal form - less nutrient leaches into the water than from a minced or paste food.
• Pre-portioned cubes - press out what you need and the rest of the blister goes straight back in the freezer.
• Freshwater diet - sized and marketed by Ocean Nutrition for small to medium freshwater species.

Full ingredient declaration

Reproduced exactly as Ocean Nutrition publishes it: Daphnia.

That is the complete declaration. Daphnia are crustaceans, so the pack carries a crustacean allergen for anyone handling it. No artificial colours, preservatives, ethoxyquin, BHA or BHT are named, because nothing beyond the animal itself is named at all.

Analytical constituents

Ocean Nutrition does not publish a crude fibre figure for this product, so none is shown here rather than estimated.

Why 2.3% protein is not a low-protein food

A frozen analysis is measured wet, a flake analysis is measured dry, and the two numbers are not comparable as printed. At 96% moisture, only 4% of the cube is solid.

Dividing the published protein by that solid fraction puts frozen daphnia at roughly 58% protein on a dry-matter basis. The practical consequence is not that the food is weak, it is that a large share of every cube is water going into your tank.

Ocean Nutrition's direction is to feed 2 to 5 times a day, thawing the number of cubes you need and offering only what the fish will clear within five minutes.

Press the cubes you want out of the blister into a small container and let them defrost at room temperature. Do not thaw the whole blister to get at one cube.

Straining the thawed daphnia through a fine net and leaving the pack liquid behind is worth the extra ten seconds. That liquid feeds nothing and goes straight to nitrate and phosphate.

Keep the blister frozen until the moment you use it, and never refreeze a portion that has thawed. In a Queensland summer, the trip from freezer to tank is long enough to matter - take out what you need and close the door.

Suitable for

• Small to medium freshwater community fish - tetras, rasboras, barbs, danios and livebearers
• Fancy goldfish and bettas, where the shell roughage is the reason for feeding it
• Juvenile cichlids and other growing freshwater fish, as one food in a varied diet
• Freshwater shrimp and small bottom feeders that will pick up what settles

Not suitable for

• Use as a sole diet - at 2.3% protein wet this is a supplementary and conditioning food, not a staple
• Newly hatched fry and larvae - a 2 to 3 mm animal is too large for most first-feeding mouths, and Frozen Rotifers 100g at 0.2 mm is the food for that job
• Large predatory freshwater fish, which will not register a 2 to 3 mm item as food
• Marine reef feeding - Ocean Nutrition markets this one for freshwater species
• Automatic feeders, which cannot handle a frozen wet food

• Frozen Bloodworm Spirulina Garlic 100g - a richer frozen blister for the same freshwater fish on alternate days.
• Frozen Tropical Mix 100g - a mixed frozen blend so the week is not all one organism.
• Frozen Rotifers 100g - the 0.2 mm option for fry too small to take daphnia.
• Frozen Artemia Brine Shrimp Flat 454g - bulk brine shrimp once you know the fish take frozen food reliably.
• Frozen Veggie Favourites 100g - plant matter for the herbivores sharing the tank.

Aquarium foods carry no manufacturer warranty period. Your rights under the Australian Consumer Law apply in full and sit in addition to anything a manufacturer offers, including a remedy if a product arrives thawed, damaged or not of acceptable quality.

This is a frozen product and is handled as cold-chain stock. It travels by in-store pickup or local delivery rather than standard parcel post, because a blister that thaws in transit cannot be refrozen.

Is frozen daphnia useful for a bloated or constipated fish?

Ocean Nutrition states that the hard shell of daphnia provides roughage that facilitates digestion, which is the reason daphnia has been fed to bloated fancy goldfish and bettas for decades. It is a dietary measure rather than a treatment, and persistent bloating in a fish needs the water parameters and the rest of the diet looked at as well.

Do I need to thaw the cubes before feeding?

Yes. Ocean Nutrition's direction for the Nutris blister range is to thaw the desired number of cubes before feeding, unlike some of its formula cubes which are designed to be dropped in frozen. Ten to fifteen minutes at room temperature in a small container is enough.

How much of a 100 g blister do I feed at once?

Feed only what the fish will finish within five minutes, which for most home aquariums is a fraction of a single cube rather than a whole one. Start with a quarter of a cube for a small community tank and adjust by what is left on the substrate after five minutes.

Will frozen daphnia cloud the water?

The pack liquid is the main cause of cloudiness, not the animals. Straining the thawed portion through a fine net and discarding that liquid before feeding keeps the water clear and keeps the nutrient load down.

Can I refreeze a blister that has partly thawed?

No. A thawed frozen food should never be refrozen, because the texture breaks down and the bacterial load rises. If a blister has gone soft, feed what you can use immediately and discard the rest.

How long does an opened blister keep in the freezer?

Ocean Nutrition does not publish a shelf life after opening for this product, so no figure is claimed here. In practice the limit is freezer burn: cubes kept in a sealed bag or container inside the freezer hold their quality far longer than a blister left open to circulating air.