Large White Spots on Pond Goldfish: Ich Treatment Urgency

Ichthyophthirius in Established Pond

One goldfish with 4 large white spots; 10 others clear. Pond 15+ years old, inherited.

Action Required NOW

1. Treat entire pond—Ich spreads fast. All fish will be infected within days.
2. Use pond-safe Ich medication (malachite green/formalin based, e.g., ProForm-C, KoiZyme).
3. Remove carbon/UV during treatment.
4. Add salt 0.1% (1 kg/1000 L) to disrupt parasite.
5. Raise temp if possible (not always feasible in pond).
6. Complete full course (usually 3–5 treatments over 10–14 days).

Reference

Ich Life Cycle & Treatment.

Delay = total loss. Treat immediately.