Salt As a Medicine

for the week of 4/15/99

An almost forgotten treatment for many common freshwater fish parasites is plain old aquarium salt. Used properly, a saltwater bath can be very effective in eliminating “ich,” velvet, Trichodina, Chilodonella, and a number of less common parasites.


Salt treatments are:

  • Very cheap – especially for large tanks or ponds.
  • Effective on many different parasites
  • Unlikely to put ill fish “over the edge”
  • Safe for many species of fish
  • Hard to overdose
  • Unable to break down or get absorbed during treatment
  • Unable to stain tank sealant
  • Measurable (Aquarium Pharmaceuticals’ Salt Level Test Kit)


Salt treatments are:

  • Dangerous to most plants
  • Dangerous to certain fish (e.g. Corydoras catfish)
  • Ineffective against gill flukes
  • Removable only by water changes

Best uses. Salt is a treatment of choice for most pond fish, including goldfish and koi, which are somewhat sensitive to other common ich medications. It is also very cost effective for use in large bodies of water. In addition, certain ich-prone but malachite green sensitive species, such as “High Fin Bull Sharks” (Arius jordani) are easily treated with salt.

Dosage. Use one teaspoon of non-iodized (aquarium, canning, Kosher, etc.) salt per gallon of water every 12 hours for a total of three treatments (total dose: 3 teaspoons per gallon). For ponds or huge aquariums, use 1 pound of salt per 100 gallons every 12 hours for three treatments (total dose: 3 pounds per 100 gallons). In cases where parasites are overwhelming fish, full dose may be added at once.

“Tip of the week” appeared regularly in 1999 and 2000.