Why we need to add salt in fresh water tanks

andy_

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Jul 18, 2014
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Im new to this forum, may i ask some question pls...

What do salt do with the fresh water fishes? Do i need to add some salt with my fish? I had

14" rtg arowana
2 red tail cat fish
4 clown loach
7 tin foil barb
5 silver dollar
And
3 hi fin shark

If i do need to put salt, how much salt i should put? I have a 500gal tank. Im very curious about the adding salt thing... I really don't have any idea why do we need to put salt in fresh water tanks? Hopefully you guys answer my question or send me some links to read on...

Thanks
Andy,
 

duanes

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None of those fish need salt.
I never add salt, unless treating for some kind of halophobic parasite.
Or if the water in your area is extremely soft (5ppm hardness for example)
but many of the the fish you list, are from soft, non salty water.
 

RD.

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What he said. ^


To add to that, I will add a pinch or two of salt to a tank when transferring fish, adding newly acquired fish, or transporting fish to help reduce osmoregulatory stress.
 

chopsteeks

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What he said. ^


To add to that, I will add a pinch or two of salt to a tank when transferring fish, adding newly acquired fish, or transporting fish to help reduce osmoregulatory stress.
'osmoregulatory' --- a bit deep for me, can you explain what this means ? Thx.
 

GeraldOngSL

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Drstrangelove

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None of those fish need salt.
I never add salt, unless treating for some kind of halophobic parasite.
+1

Salt is useful for treatment as certain parasites are controlled/eradicated by small salt doses. At low levels, salt has limited or no short term harm with most fresh water fish.

There are, to my knowledge, no long term benefits to maintaining a low but constant level of salt. However, since freshwater fish have evolved (from marine fish) for an extensive time outside of salt water, there is a reasonable chance that while they may tolerate salt for a short time, there may be harm if it's done long term---but that also is not documented.

Also, each fresh water species has a different tolerance level. What is tolerable by one may kill another.
 

RD.

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There are, to my knowledge, no long term benefits to maintaining a low but constant level of salt.

I can think of one, which may possibly apply to other pathogens as well.



http://www.veterinaryresearch.org/content/44/1/27

6.1 Preventive measures

If the fish can be adapted to salt levels of at least 1.0‰, this method could be used as a possible preventive measure in columnaris disease


But as you stated, different freshwater species may have a different tolerance level towards sodium chloride. What may be beneficial to one species, could be harmful to another.
 

Drstrangelove

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I can think of one, which may possibly apply to other pathogens as well.

http://www.veterinaryresearch.org/content/44/1/27

6.1 Preventive measures


But as you stated, different freshwater species may have a different tolerance level towards sodium chloride. What may be beneficial to one species, could be harmful to another.
Good point, although I think I was working along different lines.

There is ample evidence that salt is useful:

1) to reduce stress during fish movement and capture
2) to control or eliminate parasites
3) to encourage feeding for stressed fish
4) to encourage injury repair
5) offset nitrites in the tank

(I may have missed others which was inadvertent. And I am referring to FW fish who evolved in salt free water.)

I 100% agree that it has valuable purposes. But it's value (seems) most apparent when it's used to ward off a different more dangerous condition (stress, capture, parasites, starvation, nitrites, open wounds.) When a fish is in a tank with clean water, no parasites, is not stressed, is not being moved, has no injuries, and is feeding, the value of salt is much less supported. Preventative---curative---absolutely.

In the absence of need, I would hypothesize it's more like taking vitamins for someone who is already healthy and eating a healthy diet. Not needed, but the more you take, the more injurious it becomes.

Salt for freshwater fish may indeed be good---regardless of the presence of parasites and injuries---dosing a tank at low levels with salt may indeed have good LT benefits. Perhaps if one takes certain (or many) species and raises them from fry to fully aged adults, they will grow better and live as long (or longer) than fish not raised with salt. I'm just skeptical.

Here's a few studies I found that tried to evaluate various salinity levels effects. I wish I could say it was clear, but the effects are all across the board. Some good effects, some bad effects.


http://fl.biology.usgs.gov/projects/tilapia_salinity.html
http://www.tandfonline.com/doi/abs/...<0545:GOLBIL>2.3.CO;2?src=recsys#.U-Q0WvldVZ8
http://pubs.er.usgs.gov/publication/70056141
http://www.arkansasstripers.com/salt-and-shad.htm
http://www.thefishsite.com/articles...e-on-atlantic-salmon-postsmolts-reared-in-ras
http://www.ehp.qld.gov.au/water/pdf/potential-impacts-sal-tur.pdf
 
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