Fish with Swelling & Floating: Costia Parasite, Salt Bath & Pond Disinfection

Two fish: lethargic, color loss, belly swelling, eye swelling, floating. Costia parasite — thrives in dirty water.

Emergency

1. Hospital tank: Same temp/pH, filtered, aerated.
2. Salt bath: 1 kg / 100 L (1%), 12 days max.
3. Treat all fish — Costia spreads fast.

Pond Disinfection

• 3 kg salt / 100 L in empty pond — 2 days, then drain, rinse.
• Kills free-swimming parasites.

Costia Facts

• Microscopic flagellate — gills, skin.
• Dirty water, crowding, stress = outbreak.
• Salt = reliable cure.

Swelling + floating = Costia. Salt bath + pond salt soak. Clean water prevents return.