Common Freshwater Fish Diseases

Prevention Is Better Than Cure

Most diseases are caused by stress. Healthy fish in good water rarely get sick. Maintain excellent water quality, proper nutrition, compatible tank mates, and quarantine new fish.

Common Diseases

Ich (White Spot)

Symptoms: White spots like salt grains, scratching, clamped fins.

Treatment: Raise temp to 30°C over 24h + ich medication. Repeat 7-10 days through two lifecycle cycles.

Fin Rot

Symptoms: Frayed, ragged fins. White/brown edges.

Treatment: 50% water change + antibiotics (Kanaplex). Mild cases resolve with just clean water.

Velvet (Oodinium)

Symptoms: Gold/rust dust on body (check with flashlight at night), rapid breathing.

Treatment: Darken tank + copper medication (remove shrimp/snails first!). Raise temp to 30°C.

Fungal Infections

Symptoms: White fluffy growths on body/fins.

Treatment: Methylene blue dip or ParaGuard. Fix underlying cause.

Dropsy

Symptoms: Swollen belly, scales protruding (pinecone appearance).

Treatment: Isolate + antibiotics + Epsom salt baths. Prognosis is usually poor.

Swim Bladder Disease

Symptoms: Swimming upside down or floating uncontrollably.

Treatment: Fast 2-3 days, then feed deshelled pea. Often chronic in fancy goldfish.

Pro Tip: Always quarantine new fish for 2 weeks before adding to your display tank. This prevents 90% of disease outbreaks.