is salt bad for corys and plecos?

[todd]

hi i have salt in my tank and was wondering if it will bother my corys and plecos. the people at my lfs always tell me to put salt in to boost fishes immune systems.

thanks,todd

[ginagv]

My understanding is that yes it would be very detrimental to cories for sure. I don't know about the plecos though, although, if it were me I would err on the side of caution and not use it. IMHO, the best thing you can do to boost the immune systems of you fish is to make sure that the tank always has clean water, testing within good parameters, and the fish are fed with good quality, wide variety, species correct foods.

that's just my 2 cents though.

Gina

[MatsP]

That's like asking if aspirin is good or bad for humans. At the right dose, in the right circumstances, it's a good painkiller, and can prevent heart-problems and all manner of other positive things. But give too much, or under the wrong circumstance, and it's going to cause problems.

Likewise, salt is a good medecine for fish, when used correctly. But where corys and plecos live, the levels of salt/minerals in the water is extremely low (generally - there may be a few species that live in quite mineral rich rivers, but that's the exception, not the rule).

I wouldn't recommend using salt "always", but under the right circumstances, yes, it can be used, in the right amount. The right amount depends on what is wrong with the fish.

Unfortunately, shops like to sell you salt, because they make money on that...

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Mats

[Coryman]

Salt for Corys & Plecos!

Well from my angle as a Cory guy, the whole thing about them being intolerant of salt is pretty much a myth. Corys come from a very wide range of condition from very acidic 'Black water' 'Clear water' and sediment rich 'White water.

I have never in forty years of Cory keeping had any issues with treating them with salt, even quite heavy doses. Dosing should not be done willy-nilly and recommended dosages per condition being treated should be strictly observed.

I think the phrase 'Catfish don't like salt' was originally aimed at 'Naked Catfishes' like Mochokidae and Bagridae to name but two and the phrase as I first read in a CAGB magazine back in the seventies read 'Naked Catfishes do not like salt'. Actually if truth be known non of them 'Actually' like salt, but as a dip treatment it does a very good job and most fish recover very well, especially if it gets rid of the parasites they were carrying and which necessitated the treatment in the first place.

Ian

[racoll]

the whole thing about them being intolerant of salt is pretty much a myth

the people at my lfs always tell me to put salt in to boost fishes immune systems.

There's one thing saying salt is an acceptable medicine to use, and another to say it should be used routinely as a prophylactic.

[MatsP]

Indeed, it is also what I was trying to say. Unless your doctor says to do so, you don't take Aspirin every day "just in case" - and if you did, it's likely you'd suffer some consequences.

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Mats

[Jools]

Isn't there are FAQ on this? So, to some all that up. Yes, in sufficient quantities salt is bad. It can be used for medicinal reasons and is not needed for a healthy regular freshwater aquarium (FWIW, I have never used it).

The OP is also asking if adding salt (I think all the time) will boost Corys immune system. At least I think that's the question being asked also?

Jools

[racoll]

The OP is asking if adding salt (I think all the time) will boost Corys immune system. At least I think that's the question being asked?

So in conclusion, I think the consensus here is that no, salt will not "boost the immune system". Good quality water, food and livestock are all that is necessary for the fishes to take care of themselves.

However, salt is an effective medicine for many ailments, and is suitable for use on both Corydoras and loricariids.

[Jools]

Yup, and if that's not in the FAQ, it should be!

Jools

[MatsP]

I will update the FAQ.

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Mats

[Coryologist]

Some magical powers attributed to salt in freshwater fish/aquariums: protection, healing and stress.

Salt and "protection." First, "Salt can aid in the production of the slime layer," you'll be told. And so could many water-born toxins or irritants, in fact. You're already aware that the fishes' normal slime covering is produced by specialized cells scattered through the epidermis. To increase their mucus production, these cells could be stimulated in two ways. One way would be through the action of a hormone. Hormones stimulate secretory cells of all kinds. But no one is suggesting that salt contains a hormone or is imagining that salt is some chemical precursor of mucus. In the other way, these slime-secreting cells could be stimulated by an irritant. After all, many irritants and toxins trigger hormones., and salt in the water merely acts as an irritant. If you've ever inadvertently half-poisoned a fish, as I have, you know that one reaction of the fish to any stressful irritant is to increase mucus production. It is true that the increased flow of mucus can help slough off incipient parasites. To this extent, you could justify saying that salt in the water "protects the fish from parasites." I find this to be stretching a point. Salting the water to increase the mucus layer is like putting a drop of lemon juice in your dry eye to make it water.

I've recently read that ammonia acts to thin and break down the slime layer of marine fish. Certainly we all know its action as a surfactant when we add a capful of household ammonia to the dishpan. If this is true in saltwater, NH3 might have a similar effect on freshwater fish. But surely you'd act to reduce ammonia levels in the water, rather than to compensate for ammonia by adding salt.

Salt and healing. The second common magical power attributed to salt is that it "aids healing." In a dry atmosphere, a salt solution helps "draw" degraded cells and pus material from the abraded tissues of a wound, thus helping to clean it. A painful procedure from old shipboard days, when lacerations from a flogging were prevented from festering by applying dampened salt, still echoes in the phrase "to rub salt in someone's wounds." This bracing concept can't be extended to a water environment. When you inquire closely from an ol' "salter" how salting the water would aid healing, you'll soon understand that it's always based on an idea of "hyperosmolarity," that tendency of a more concentrated solution to "draw" a less concentrated solution that is at the heart of osmosis. You can't "draw" a fishes' wound; brine that was more concentrated than its own blood and tissues would quickly kill a freshwater fish.

A peripheral thought. Salinity levels that approach brackish water would repress Saprolegnia-type water molds, which can attack necrotic tissue. That's not the active consideration, though, when folks say some salt added to fresh water "aids" healing.

Salt and "stress." There is another wide-spread misconception, that some salt permanently in the water is "easing the stress" of osmotic pressure. This misconception is actively encouraged by packagers of "aquarium" salt. You'll hear this old tale repeated so often that, if it came to a vote, it might be voted "true." Most likely, this mis-application of "stress" comes from the idea of osmotic "pressure." Any pressure, such as social pressure, must result in some "stress" to the organism, such as social stress--— that's the thought, anyway--— and if osmotic pressure could be reduced, or even equalized, so that the surrounding water were at the same concentration as blood and tissues, then osmotic "stress" would be reduced. The fish would have to do less metabolic "work" to maintain osmolarity in its blood and tissue. I've even been told that the energy saved could then be applied to fortifying the immune system. These "logical" conclusions aren't based on the actual physiology of freshwater fishes.

But this is a mis-reading of the meaning of "pressure" in this case. Though peer pressure may result in stress, not all pressures result in stress. For example, atmospheric pressure doesn't result in stress. And neither does osmotic pressure. Fishes have evolved to adjust within certain limits to salt levels, ranging from virtually zero to water more saline than average seawater. No species of fish however will thrive at every level. Not all fishes are tolerant of change: the few that are warrant a special designation, "euryhaline." You know these things. But you will still hear lots of well-intentioned talk about salt and "stress," often from quite experienced aquarists. Listen skeptically, and I think you'll recognize this basic mis-connection between "pressure" and "stress."

Other opinions of magic powers of salt are just chit-chat. Take them with a grain of, um, whatever...

Or compare this good cautious article from the Aquascience Research Group, which may dissuade you from adding salt to the freshwater aquarium, if I haven't been able to convince you.

Salt sellers. Okay, now you're prepared to decipher claims made for an "aquarium" salt by its packager. Here, word-for-word, are salt claims off a box of "Aquarium" salt:

"An all natural* salt, made from evaporated sea water**...providing the essential electrolytes*** fish need to survive in an aquarium: calcium chloride, calcium sulfate, magnesium chloride, magnesium sulfate, potassium chloride and sodium chloride."

*"All natural." Generic reassurance.

**"Evaporated sea water" will contain many salts beside sodium chloride. Calcium and magnesium carbonates, not listed, would affect the pH buffering and would raise the pH in unbuffered acidic water. Additional buffering may make it more difficult to reduce pH if you're administering a medication that is only effective at a lower pH. The sulfates and chlorides listed provide no pH stability.

***"Electrolytes" are any dissolved salts. Of course you know that fish can't survive long in pure distilled water alone. It's in this sense that some minimal electrolytes are "essential."

"Helps improve gill function* to reduce stress**... Reduces electrolyte loss and promotes healthy gill function."

*"Gill function" in this case refers to osmoregulation, the regulated passage of ions back and forth across the gill membrane. Salt's chloride ion blocks the uptake of nitrite. It's inconceivable that "gill function" could be identified with the gills' certral role in respiration.

**"Reduce stress" refers to osmotic "stress"

"Can be used with most* aquarium remedies to improve recovery from disease."

*Though this claim reassures you that salt will not interfere with the effectiveness of medications, "most aquarium remedies" must exclude all those that are rendered less effective by higher pH.

"Protects fish against nitrite toxicity.*"

*Yes! Yes, at last! Indeed, minute concentrations of chloride ions do inhibit the uptake of nitrites through the gill membranes.

-Quoted from an article in "1999-2005 The Skeptical Aquarist".- http://www.skepticalaquarist.com/docs/health/salt.shtml

[Bas Pels]

While I do agree with Corylogist in the above mentioned matter,s I'd like to put down an advantage of using salt

Salt prevents fungusgrowth in sweet water. An open wound will - unless it starts healing soon, become overgrown with a fluffy fungus. This fungus - if not attacked might kill the fish

Therefore, if I see wounds I use salt - that is, for cichlids coming from central America - which can have a lot of salt (3 or 4 g/l or more) in a dose of 1 g/l

In this case the salt does not heal, but it does prevent complications while healing

Still - after a discussion with a vet in training (a fish keeper) - I have to agree this is also the only thing salt does: prevent fungusgrowth and, in large concentrations, prevent ich. But in most cases better alternatives can be found

[FunkyFredFrog]

How about salt for stopping fungus in eggs when breeding? Will this act as a natural preventative measure?

[MatsP]

How about salt for stopping fungus in eggs when breeding? Will this act as a natural preventative measure?

I would have thought that there are other methods that are better - methylene blue and alder cones are two examples - clean water also helps! ;)

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Mats

[Coryman]

Salt as a fungus preventative for Cory eggs is also a no no. Corry eggs and I would suspect that most if not all fish eggs have pores which allow the males sperm to enter and thus fertalise. It takes around a few hours for the outer egg membrane to harden off and in that time salt could also enter the egg and cause infertility.

Staining agents like Methylene blue or the Tannins from Alder cones, or even almond, oak or Beach leaves will give good protection.

Ian

[dw1305]

Hi all,
I can't see any reason to routinely add salt. Most of the fresh water in S. America is very poor in all salts. Even in the white water streams flowing from the Andes piedmont sodium is only present in small amounts. The vast majority of the Loricariid and Callichthyidae catfish have evolved in low conductivity, salt poor water.

You might want to raise the KH and GH of your water (if it is extremely soft), but NaCl has no effect on this, it just raises the conductivity (measured as micro-Siemens) and adds N+ and Cl- ions. The sea is salty because plants and animals have a relatively low requirement for sodium and chlorine, and these elements have weathered out of rocks and accumulated in the sea over the entire history of the earth, as a result of this seawater has conductivity of around 54000 µS/cm.

We can work out the contribution of NaCl to the conductivity and approximate this to 0.5g of salt in 1 litre of water has a conductivity of approx. 1000 microS.
(a 0.01M solution of NaCl has 584 milligram of salt in it and an electrical conductivity of 1156 microS.).

Here are some conductivity and sodium (Na) chloride (Cl-) readings for some S. American rivers, (from Mayland & Bork "S. American Dwarf Cichlids" 1997, Verlag ACS).

Rio Orinoco, upstream of Ciudad Bolivar - conductivity microS 44, Cl- 0.55 mg/l.
Upper Rio Negro - conductivity microS 15, Cl- <3 mg/l, Sodium (Na) 1 mg/l
Rio Nanai - conductivity microS 6, Cl- 2 mg/l, Na 2.5 mg/l.
Rio Paruru, Rio Tocantins water shed. - conductivity microS 20, Cl- 4 mg/l.
Rio Burus conductivity microS 63, Cl- 3 mg/l.

So literally equivalent to no more than a grain of salt in a whole tank of water.

cheers Darrel