Fish Gasping at Pond Surface: Emergency Oxygen Checklist

All Fish at Surface Gasping—Act Fast

Gasping = low oxygen or gill dysfunction. This is an emergency.

Immediate Actions

1. Add air stone(s) now — even if you think O2 is fine.
2. Check pump/filter flow — clean if restricted.
3. 50% water change max with dechlorinator + 0.05% pond salt.
4. Test: pH, ammonia, nitrite, hardness, alkalinity, chlorine, O2.
5. Activated carbon bag in filter (toxin removal).

Common Causes

• Hot weather + high stocking + low aeration.
• Heavy rain (dilutes O2, buffers, adds runoff).
• Algae bloom crash (nighttime respiration).
• Gill flukes, chlorine, ammonia.

Don't wait. Fish can die in hours.