Large Goldfish Dying in Established Pond: Bloating & Overcrowding

Big Goldfish Dying, Small Ones Fine? Bloating Points to Overcrowding

900-gal pond, 9 large goldfish dead in 2 weeks, bloated post-mortem. New fish added 3 weeks ago. Oak leaves, iris OK, floaters failing.

Bloating = Internal Pressure

Could be dropsy, egg-binding, or bacterial — but overcrowding is the root stressor.

Stocking Math

Rule: 1 inch fish per sq ft surface. 900 gal ≈ 100 sq ft. If fish average 8" = 800 inches → 8x overstocked.

Action

• Remove bloating fish immediately to hospital tank.
• Reduce population — rehome large fish.
• Improve filtration/aeration.
• Leaf net for oak leaves.

No preventive meds — they mask problems. Fix the crowding.