Aquarium keeping you can trust

Paracheirodon innesi

Tank volume:

from 60 L

Maximum size:

up to 4 cm

Temperature:

20–26 °C

pH:

5–7

Betta splendens

Tank volume:

from 20 L

Maximum size:

up to 6.5 cm

Temperature:

24–28 °C

pH:

6.5–7.5

Poecilia reticulata

Tank volume:

from 40 L

Maximum size:

up to 5 cm

Temperature:

22–28 °C

pH:

7–8

Corydoras aeneus

Tank volume:

from 80 L

Maximum size:

up to 7.5 cm

Temperature:

22–28 °C

pH:

6–7.5

Pterophyllum scalare

Tank volume:

from 200 L

Maximum size:

up to 15 cm

Temperature:

24–30 °C

pH:

6–7.5

Symphysodon aequifasciatus

Tank volume:

from 250 L

Maximum size:

up to 17 cm

Temperature:

28–30 °C

pH:

5.5–7

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

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

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

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

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

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.

Saprolegnia (fungus) on fish and eggs — treatment and root causes

White cotton-like tufts on wounds, fins or eggs. The fungus is an opportunist — it only attacks already-stressed fish. The key to treatment is removing the underlying cause (injury, bad water, stress); the fungus itself comes off easily with methylene blue.

Internal parasites in fish: Camallanus and Hexamita — diagnosis and treatment

Red worms protruding from the vent (Camallanus) or white stringy faeces and 'hole-in-the-head' in discus (Hexamita) — two different parasites needing different drugs: levamisole and metronidazole. Detailed treatment protocol.

Gill and skin flukes (Dactylogyrus, Gyrodactylus) — diagnosis and treatment

Microscopic flatworms on gills and skin. Symptoms — fast breathing, flashing, mucus clouding. Often present latently and flare up under stress. Treatment — praziquantel.