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need someone to explain to me on this one.

do we need salt in a freshwater?
why?
when should we add?
does it alter pH or other water properties?

You dont need salt in true freshwater aquaria full stop.For some catfish, including corydoras, its use can be lethal.

Its sometimes added for a number of reasons.

1) Fish that are loosely described as freshwater, but are in fact from estuaries, seasonal pools that dry in high salinity soil areas, and sinotes need a little salt but couldnt be considered consistantly brackish. These include sailfin mollies, some other mollies,a few small rainbowfish species, a few puffers and so on.It radically increases their health and longevity to give them mild or occassional exposures to salt.There are a few uncommon cichlids in this situation too. This is presumably how the myth about salt being good for all fish got started. Salt simply does not have a positive effect on the health of all species, just a select few.

2)You definately need salt for true brackish species like dragon gobies, archerfish, four eyed fish etc. Without it they will suffer osmotic balance failure, and either their tissues will start to lose fluid or gain it radically,and this is fatal.Its hardly worth mentioning that marine species obviously need salt .

3) Salt is used if there is a medical need, but unfortunately its not particularly effective as a cure for much. It has a peripheral effect on most parasites and none on others, its not a true cure.Its kind of a placebo effect (for the fish owner) that is really a hangover from the 60's and 70's when better cures werent available.Its use is in a lot of old literature and people keep using it . Basically exposing a fish to salt baths can have a mild positive effect , but half of the conditions salt baths are supposed to be used against actually take a not dissimilar amount of time to be killed by the salt as your fish do.The theory is, that saltwater bacteria and parasites cant cross over into freshwater and vice versa, unfortunately this is not entirely true, and a number of diseases, especially those caused by mycobacterium have no trouble in passing the osmotic barrier whatsoever.Its what you call , a low cost, low success rate treatment. It usually only ever makes a difference in certain bacterial and parasitic diseases if they are caught very early indeed, Often it just subdues the symptoms rather than actually cure the problem. Salt is occassionally used to help fish already suffering from osmotic issues, but more often than not, it probably makes things worse.Ironically enough some marine fish keepers put saltwater fish into freshwater for short periods to treat using the osmotic barrier principle too. This is pretty much just as lame as putting freshwater fish in salt, but hey, people will do anything to avoid spending ten bucks on the proper medications!

4) The biggest reason people use salt, is as a tonic, which most of the time is completely pointless, since for true freshwater all it can do is cause irritation. It might kill a few bugs , but it does nothing that you wont already have done in providing a fish with a good immune system via diet, and decent water quality. Basically its widest use in aquariums worldwide is simply people faffing about, feeling like it ought to do the fish some good.Generally it does nothing, unless you have a species with a real environmental need for higher salinities.Most of the time all people are doing by adding salt is making it harder to grow plants in their tank!

Adding salts can obviously harden water,as it is obviously a dissolved solid and will affect the conductivity of the water, but its not the same as calcium hardness or carbonate hardness, unless the tonic salts are very impure. Basically it depends where you source it from. As for ph that too can change, because salt will affect bacteria , plant and algae growth, this affects the decompositional processes in the tank, and that in turn affects ph, so it might cause a small change of readings. Salt is certainly not chemically inert as regards ph, but most tonic salts are selected to have a minimal effect.

When it comes to true freshwater aquaria some people will swear by using salt, but personally ive never had to and can't see a reason in the world why I would ever want to. Nobody needs it, its just something that people feel they ought to do.

Yep, there's no need for it. If you have fish that are totally freshwater, there is no need to add "aquarium salt" to your water. With fish that are brackish, salt is necessary but not the aquarium salt stuff. Those fish need marine aquarium salt, just administered at a lower dosage.

No one has been able to prove that salt in a freshwater tank is beneficial, and nobody has proven that it is harmful. My opinion is that the fewer products we add to our water, the better. Since there isn't a reason to add salt to the water, I won't do it. People using tapwater already have salts and minerals present in some quantities, and those are enough for the purposes of the fish.

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And when he gets to Heaven, to Saint Peter he will tell: "One more Marine reporting, Sir! I've served my time in Hell."

Hi,
Here is a site that you might be interested in:

http://edis.ifas.ufl.edu/VM007

Decades ago, salt was used primarily to help combat
Ich. The idea was that one would raise the temperature
of the tank (we still do) because the increased temperature
would cause the parasite to accelerate its life cycle.
The only time the parasite is easily killed is when it is
in the free swimming stage of its cycle.

By adding salt to the water the metabolism of the fish
was stressed and it produced larger quantities of slime.
The idea (theory) was that the constant, increased
quantity of slime would slough off the parasite before
it could attach itself to the fish. If it could
not attach, it could not feed, and would die.

Once the Ich was killed off, it was frequently used as a
prophylactic to help prevent further outbreaks of Ich.

Other fish such as mollies actually required some salt
in their water. There is some dispute about that now as
initially the fish were wild caught from streams that had
salt in the water. Some folks say that now, also decades
later, that over the generations of breeding the fish,
they have been weaned away from the salt and it is now
no longer necessary.

With the salt in the water some say that their live
bearers have more vivid coloration.

All in all, its up for grabs and up to the fish keeper.
Those who use salt know that you do not add salt to the
water when topping the tank off for evaporation. The know
that salt does not evaporate. They know that the only
time you add salt is during water changes and to dose for
the number of gallons actually removed from the tank.
New folks to the hobby don't always realize this very
KEY POINT and add it every time they put water in the tank.
At that rate the water rapidly becomes too salty and can
kill the fish and plants.

Frank

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