Can I Use Rock Salt Instead of Pond Salt?

Rock Salt vs. Pond Salt: Yes, They're Interchangeable

Yes. Rock salt (halite, NaCl) is chemically identical to pond salt. Use the same dosage.

Dosage Guidelines

• General tonic: 0.05% (0.5 kg per 1000 L / 1.25 lbs per 100 gal) — safe with plants.
• Therapeutic bath: 0.1–0.3% for 5–10 minutes in a separate container — kills parasites.

Important

• Use pure salt — no anti-caking agents (yellow prussiate of soda), no iodine.
• Dissolve fully before adding.
• Monitor with a salinity meter or hydrometer.

Rock salt is cheaper and widely available (feed stores, hardware). Just verify purity.