Dropsy in Koi: Emergency Salt, Plant Removal, and Water Quality

2000-gal pond, 13 small koi. One 18" koi shows dropsy (pineconing, bloated). Expert recommends 0.6% salt + 82°F. But you have lotus/lily (salt-sensitive) and can't heat. What to do?

Reality Check: Dropsy Is Usually Fatal

By the time scales pinecone, organ failure is advanced. Salt/heat may buy days/weeks but rarely cures. Focus: protect the other 12 koi.

Immediate Actions

1. Remove Plants: Lotus/lily to tubs in garage/basement (40–50°F, dormant). They'll survive winter.
2. Salt Main Pond to 0.3% (3 lbs/100 gal): Safe for koi/goldfish. Supports osmoregulation, reduces parasite load. Do over 2–3 days.
3. Test Ammonia/Nitrite: Must be 0.00. If not, 20% daily water changes + prime.
4. Add Salt-Tolerant Bacteria: (e.g., Microbe-Lift PL) to maintain biofilter.
5. Quarantine Sick Koi (Optional): Hospital tub with 0.6% salt, 75°F (heater), air stone. Medicated food (kanamycin). But stress of capture may kill her.

Why 0.6% Salt + 82°F Is Impractical Here

• Heating 2000 gal to 82°F in winter = $100s/month.
• 0.6% salt kills plants, some beneficial bacteria.
• Stress of moving a 18" koi is huge.

Best Path

Salt main pond to 0.3%. Remove plants. Pristine water. Monitor others. If sick koi declines, euthanize (clove oil). Learn from it: quarantine new fish, test water weekly, don't overstock.