Live and frozen fish food: the guide to getting started
Live and frozen food is the best complement to flakes: closer to the natural diet, it revives colours, stimulates breeding and wakes up picky eaters. One or two feedings a week are enough. Expect 3 to 6 € for a 100 g frozen blister pack, 4 to 8 € for a bag of live food.
Why supplement the flakes?
Dry foods are convenient and complete on paper, but monotonous. In the wild, almost all our aquarium fish hunt: insect larvae, small crustaceans, worms. Live prey triggers that hunting behaviour — excellent enrichment — and its fresh protein profile visibly improves fish condition within weeks. It’s also the clinching argument for getting a sulking betta to eat or conditioning a pair for breeding.
Live or frozen: which to choose?
- Frozen (blister packs): bloodworms, brine shrimp, daphnia, krill. Safe, available year-round, keeps 6 months in the freezer. 3 to 6 € per 100 g.
- Live in bags: brine shrimp, daphnia, Grindal worms. Maximum appeal, but use within 2 to 3 days. 4 to 8 € per bag.
- Home culture: a brine shrimp hatchery (15 to 25 € for the kit, eggs at 10-15 €) for fresh nauplii, perfect for fry.
- Freeze-dried: acceptable as a backup, but less nutritious; rehydrate before feeding.
How do you feed without polluting the tank?
Thaw the cube in a glass of tank water, then pour it through a fine strainer and discard the thawing juice, which is highly polluting. Feed only what the fish eat in 2 to 3 minutes: leftover bloodworms buried in the substrate send nitrates climbing, as your water tests will confirm. When you’re away, stick to dry food via an automatic feeder: frozen food can’t be automated.
Are there any health risks?
Commercial frozen food is sterilized by freezing: the risk is close to zero. Bagged live food is safe if it comes from a culture; on the other hand, prey netted in wild ponds can bring in parasites, hydra or predatory dragonfly larvae. Live tubifex, harvested from polluted waters, are the riskiest: choose them frozen. All our nutrition guides are in the food category.
Frequently asked questions
Can you feed frozen food exclusively?
It’s not ideal: some packs lack vitamins. The winning balance is still a quality dry staple plus two live or frozen meals a week.
How many fish does one frozen cube feed?
A 3 to 4 g cube feeds a 100-litre community tank. For a nano, cut the cube in half or thirds with a knife while still frozen.
Do shrimp eat frozen food?
Yes, brine shrimp and daphnia go down well, but in moderation: their diet should remain mostly plant matter and detritus.
This guide is part of Planète Pets’s Fishkeeping universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.