Salt Baths for Fishes
by S. N. Nagendra
We have all given salt baths to fishes. A short-period-dip and they are out, back to
the tank. Many times we have also seen that the moment they are released back into main
tank they wriggle about, run randomly, dart back and forth, etc. with heavy breathing.
Hardy type fishes survive, the sensitive ones die! Why does this happen? Read further to
Salt as medicine:
Whenever a fish is affected by external parasites or injuries, it leads to infection.
Basically because the water in which the fish live contains several different kinds of
bacteria and although they are normally good, infection may give rise to bad ones.
As a response to the infection on the fish's body (inflammatory response), there will
be an increase in the water content of the involved tissues.
Water tends to follow salt. Hence, a fish placed in a dip-tub with a high concentration
of salt tends to lose water due to osmosis (the movement of water molecules from an area
of high concentration to an area of low concentration).
Cell membranes are completely permeable to water; therefore the environment to which
the cell is exposed can have a dramatic effect on the cell.
If the tank water has a higher salt concentration than the fish's intrinsic salt
concentration, it will tend to draw out some of the fluid from the infected cells of the
fish thereby killing the infectious bacteria. This will give some relief to the fish, but
the fish will feel an energy burnout.
After salt bath:
The fish when placed in the main tank after a salt dip, tends to absorb a lot of water as
the salt content will be high inside its cells
therefore there is a possibility of
cell rupturing happening inside the fish's body
which may even lead to the death of
the fish within a few minutes. This is definite if the fish is of a delicate species.
Hence, once the salt bath is done, don't remove the fish from the bucket immediately.
Instead, add water slowly to the bucket until the concentration of salt becomes
negligible. Then, after a brief period of confinement, move the fish back to the main
tank. Make sure it is adapted to the main tank temperature. This ensures that the fish
will not be affected by sudden changes in water conditions.