Table salt usually contains iodine, which the fish needs but gets from the fish food. Any more iodine than that and it becomes a detriment. Salt should be used during times of stress to the fish, such as during an outbreak of a disease.

Is iodized salt bad for fish?

Use of Iodized Versus Non-iodized Sodium Chloride in Therapeutic Dips and Baths for Freshwater Fish. Salt (NaCl) is a common therapeutant in fish culture. The use of salt containing iodine may be harmful to fish. ... The use of iodized salt for baths and dips appears to be safe in the three species tested.

Can I use iodized salt for bait?

Salt is Critical

Kosher salt is usually preferred because it dissolves easily. ... Iodized salt should never be used in the bait brine recipe as it will turn the bait brown.