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Ichthyologist-reviewed guides, species profiles, and an interactive simulator to plan your tank without trial and error.

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Featured expert guide

Dry food for aquarium fish: flakes, pellets, wafers — the complete guide

How to read the label, which brands actually work, flakes vs pellets, and why 'cheap food' is a beginner trap.

Read the full guide
Dry food for aquarium fish: flakes, pellets, wafers — the complete guide — aquarium cornerstone guide

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Latest articles

Articles
Filters and aeration for aquariums of every size — the complete guide — aquarium guideDeep-dive
Intermediate11 min read

Filters and aeration for aquariums of every size — the complete guide

How to size a filter to your tank, calculate turnover, pick the right type, and decide if you need extra aeration. From nano cubes to large biotopes.

Aquarium fish diseases — diagnostic algorithm and 8 key conditions — aquarium guideDeep-dive
Intermediate12 min read

Aquarium fish diseases — diagnostic algorithm and 8 key conditions

How to spot illness by behaviour and look, a four-step diagnostic protocol and treatment outlines for the 8 most common diagnoses: ich, velvet, columnaris, dropsy, swim bladder, saprolegnia, internal parasites, gill flukes.

Velvet disease (oodinium) in aquarium fish — symptoms, treatment, prognosis — aquarium guideDeep-dive
Intermediate4 min read

Velvet disease (oodinium) in aquarium fish — symptoms, treatment, prognosis

Golden-grey 'dusty' coating on the skin, fast breathing, loss of appetite. A dangerous dinoflagellate parasite — treated with darkness, copper and heat. Without therapy, mortality in 3–7 days.

Columnaris in aquarium fish — telling it from fungus and treating it — aquarium guideDeep-dive
Intermediate4 min read

Columnaris in aquarium fish — telling it from fungus and treating it

A bacterial disease often mistaken for fungus. Greyish-white cotton-like patches on head and fins; the aggressive strain can kill in 24 hours. Treatment — antibiotics, lower temperature, salt.

Dropsy (pinecone) in fish — what it is, causes and odds of saving them — aquarium guideDeep-dive
Intermediate4 min read

Dropsy (pinecone) in fish — what it is, causes and odds of saving them

Raised scales, bloated belly, bulging eyes — not a disease in itself but a symptom of severe internal infection. Prognosis is grim: fewer than half survive even with correct treatment.

Swim bladder disorder — why your fish is swimming on its side — aquarium guideDeep-dive
Intermediate4 min read

Swim bladder disorder — why your fish is swimming on its side

The fish floats belly-up, lies on its side, can't hold its position in the water. Causes range from simple constipation to bacterial infection and congenital deformity. A clear diagnostic and treatment plan.