Adding salt to a freshwater tank..why? What are the benefits?

Question

I've heard a lot about it.

Would it benefit my fish? (2 mollies (planning to get another as one just died), 3 cory catfish in a 28L aquastart 320 tank)

I take it it's not just table salt either?

Answer 1

Okay, this is what it does: it strengthens the fish's slime coat (which usually protects the fish from infection/parasites), and can get read of a bacterial disease flowing through your tank. I've been using freshwater aquarium salt for a couple years now, and my fish have been doing better than ever. The salt dissolves pretty quick in the tank, but keep a close lookout on the cories. When they see the salt, they think it's food and tend to want to eat it, and that can send them going on some crazed rush (like a person on a sugar rush, y'know?). It won't kill them or harm them in anyway, but they can get a little stressed from it.

Answer 2

Adding salt is fine for goldfish and live plants. It is even recommended. Goldfish are alot more prone to swimbladder disease and problems, so more salt is recommended for them. Normal, uniodized rock salt is the best salt to add to a freshwater tank. One half teaspoon per gallon is the normal amount, but if your fish develop swimbladder problems, which can be extremely fatal, simply increase to one teasopoon per gallon and do a one-third water change. just make sure you dont put any salt in when water evaporates, because salt doesnt evaporate with the water. Only replace salt when you do water changes, which with multiple goldfish should be at least once every two weeks, every week if you have more than one per ten gallons of water. So, you have nothing to worry about. Salt is a healant, to increase the speed of the healing process when a wound is present. It is also a preventative that keeps diseases and parasites away. Do not worry about it! Have fun!

Answer 3

Do not add salt to a cory tank! They do not do well with it. They are pretty finicky where water quality is concerned, particularly the salt content, and the pH. The mollies really NEED the salt... and now, you see the dilemma. These fish are not found together in the wild, and they really do need different environments. Do not use iodized salt for any reason. Rock salt, the kind you use for pickling or ice cream, sea salt formulas, from the pet store, and even kosher salt will work. Anything that you can eat will generally work, except iodized.

Answer 4

Although I’ve never had fresh water fish I can only speculate why one would put salt in a fresh water tank. It has to do with parasitic organisms that attack fresh water fish. Parasites are really invertebrates, and if you change the salinity of the water you will also change the osmotic pressure on their bodies, causing them to die. They will actually explode (no kidding). The fish however, can take small amounts of salt. In the case of your mollies there would be no problem at all exposing them to salt water.

If the reverse is done to salt water fish (giving them a fresh water bath) the same thing will happen to the saltwater parasite.

And your right, don't use table salt.

Answer 5

it would not. salt is sometimes said to benefit fish, but it is more beneficial in a quarrentine tank where the fish are sick. NO SALT, it can only do harm right now. actually, chack out tfh magazine, in 2005 i think there was an excellent article on salt.

Answer 6

It can be table salt, as long as it's the type without iodine added. Most people talk about the use of aquarium salt, but kosher, canning, pickling, rock (the type for making ice cream), and table salt without iodine or anti-caking agents are all the same thing (NaCl), but the ones from the supermarket will cost less.

There's a lot of debate over whether or not salt should be added on a regular basis, even among people who keep fish. I use it for most of my fish, every since I found out (through a breeder) that it lowers the mortality rate for new guppies.

One of the most common uses for salt is to relieve the effects of high nitrites in the water on fish during the cycling process. This is because salt (chloride specifically) reduces the amount of nitrite that takes the place of oxygen in the fish's blood (ever wonder why they're gasping for air if you don't change the water soon enough?). Fish suppliers use a fairly high salt concentration when shipping fish to your pet store - especially if they come from overseas - all those fish together in a little bag for hours at a time produce a lot of wastes, to the point where sometimes the water's so cloudy it's hard to even see the fish. The use of salt during shipping has somewhere in the range of 90% better survival rate over shipping without it.

Other common reasons given for it's use are stress relief and disease prevention, although the "stress relief" is most likely related to reduced nitrite uptake as explained above.

Salt "baths" are a traditional remedy to remove parasites and other pathogens because they don't tolerate salt as well as the fish. Hobbyists , aquaculturists, and veterinarians have recommended low amounts (around 1% or less concentration, usually around a tablespoon per per 5 gallons of water volume) in the aquarium as a safe level for preventation for diseases and parasites. This works by something called osmotic pressure/osmotic balance - a fancy term for the amount of salt and other ions (electrolytes) inside the cells of a fish compared to the amount outside. Salt can easily be expelled from a fish through the gills. So why, then, is there a consistantly higher concentration inside their bodies than outside for freshwater fish? Freshwater fish have specialized cells to help in gathering salt ions from the water. In fact, maintaining this salt balance makes up about 25-50% of the energy expended by a fish. Basically a fish is better adapted for taking in and using salt than are the diseases and parasites that infect them. Higher concentrations can also stimulate fish to produce an excessive slime coat to prevent some of the parasites/pathogens from attaching to the fish (at this concentration, the salt can be stressful to the fish as well).

A fish also uses the salt in other ways. The chloride ions, in addition to use to inhibit nitrite uptake are used in the production of hydrochloric acid - used for food digestion. Sodium ions are used for cell metabolism in a unique way, called "active transport". Not all materials can move freely into an animals' cells. Some require "help", and sodium ions are part of the help, particularly in the movement of potassium, which is used in fluid/electrolyte balance, muscle contraction, and nerve impulse conduction. This type of transport also occurs in humans, too.

Some fish are more sensitive to salt than others, and some are more efficient at aquiring it as well. This should be considered when deciding whether or not to add it, or how much should be added. While it's not absolutely necessary to add it to a tank (and many who don't have kept fish successfully), I've found that by using low amounts that's I've had fewer problems with disease and mortality than I had before I began it's use.

Your mollies would appreciate a small amount of salt, as they are really brackish water fish that are adapted to being kept in freshwater. Your corys on the other hand are one of the types that are sensitive to it. That's not to say they can't be kept in water with a little salt, but that the concentration should be kept low, and the concentration should be built gradually, not the entire amount for the tank added at once. Once the concentration you want is established, you can just add back the amount needed to replace what is removed during water changes (if you top off the tank when water evaporates, use only fresh water, since the salt doesn't evaporate - it stays in the tank).

I'll provide some links below for sources and further reading for those interested.

pros and cons of salt use, use of table salt :
http://www.skepticalaquarist.com/docs/health/salt.shtml

see "osmoregulation" about halfway down the page:
http://www.oxyedge-chum.com/oxygen_or_salt.htm

animation of how salt is used in active transport (sodium/potassium pump):
http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/ion_pump/ionpump.html

Answer 7

I always add salt to my tank with each water change. You have to be sure it is not iodized!!! If it is it will kill them. As someone said earlier it helps protect the slime coating and it is also good for the prevention of ick.

Answer 8

your mollies wouldn't mind it. they sometimes live in brackish water in the wild. not so sure about the cories though. NON- idolized salt should be used. i don't think there'll really be much benefit to it though unless you got disease goin in your tank.

Answer 9

That only works if you have saltwater fish... tho i guess you could try it with freshwater guys and watch em turn into little fish pickles
and no, you can get salt water or the salt to go into the water at your local pet store

Answer 10

If u have fresh water fish
There are no benefits you want dead fish