Salt may actually benefit some parasites.

afremont

I have always used 1Tbsp/5gallons approx 750ppm of salt. I admit that I don't grow plants, I grow fish in my tanks. I also don't have salt sensitive fish. I do have some serpae tetras that are beautiful and healthy even though they should be long dead.

The paper that Byron is referring to does not make a scientific point with the salt and characyns. The author(s) actually included that information from "aquarium literature that they had read in the past". There is apparently no reference to actually be verified. I feel that Byron should make this clear when referencing that paper and those authors. As I recall, there is no scientific evidence presented to support the claim that 60ppm stresses characyns and leads to their death.

As for salt in the eye, if the fish were any where near that bothered by salt they'd be flashing and jumping like mad. I think it would be allot closer to the truth to say that the salt is no more of an actual irritant (in terms of pain) to them than it is to you when you put your hands in the tank. And you don't even have a slime coat. I have never seen a fish released into my tank that acted the least bit bothered by the water.

I also disagree with the kidneys working harder when salt is in the water. All of the medical literature that I have read indicates the exact opposite. Since the denser water is having a harder time penetrating the fish, the kidneys work less to remove the excess water actually lowering the stress level on the fish's internal organs. Now if someone could supply some scientific information that indicates otherwise I will be happy to rescind my remarks.

yyankeeyankeefan

so can salt be beneficial to the fish? they are guppies in that tank. they are breeding, eating fine, and seem to not have any stress or anything. and my plants are not suffering any at the amount of salt i place into the tank. only one of my plants is in the process of recovering from an aggressively lonely male dalmatian lyretail molly. (he is fine now that he is with his own kind in a bigger tank) i would like to hear more on both sides of this please.

i am reading up on this online. a common thing i am finding is that livebearers can do better with salt in the aquarium. the tank i am currently using it in is just guppies at this time. so should i continue this or just go for straight fresh water? please tell me what you would do and why.

afremont

I will not recommend using or not using salt continuously to anyone. I think it's up to the aquarist to do his/her own research and make that determination for themselves. By that, I mean for folks to read from more than one source and use their own independent thought processes. To be fair, there are plenty of fish species that are known to be extremely sensitive to salt, I just don't have any of those so I choose to use salt. I haven't experienced any negative aspect from using it so far, so I will continue until I do see a problem or I read something truly scientific that indicates that I shouldn't be using it where I can. Hyperbole about salt in the eyes and such don't interest me, that is not science. Simple observation of the fish will demonstrate the inaccuracy of that analogy.

This latest article here chose a salt tolerant fish and salt tolerant parasite (that appears to primarily attack said fish) to make their case. Does that seem like science that one can draw broad conclusions from? They proceed to make their argument by using extreme levels of salt that they claim are commonly used by aquarists. My personal research indicates those levels of salt are only recommended as temporary baths or even dips. I have personally never seen anything recommending more than 750ppm of continuous salt use which is below their lowest test amount, most salt "enthusiasts" recommend much less than that. Where the "researchers" got their numbers from we'll never know since the link is to a personal interpretation of the actual research.

You were using approx 130ppm of salt, did your fish seem stressed? Have you ever had an ich outbreak? How about fin rot? Nitrite poisoning? Just asking.

yyankeeyankeefan

no i have never had ich, fin rot, or ANY problems with my tank. only had some fish that got attacked from the molly that was in my tank. but they healed quickly and are swimming fine once more. i currently use less then what the package recommends. i used 1 teaspoon per 10 gallons, this being because i have live plants in my tank. they don't seem to be effected at all. i have had the same fish in this tank for a couple months now. would trying them in freshwater harm them if they have adapted to my current water conditions?

afremont

It's your tank, you should run it as YOU see fit. If you want to switch to unsalted water, I wouldn't recommend doing a 100% change to do it. Just cycle it out with your regular (weekly?) water changes. Keep in mind that four 25% changes will not remove all of the salt since you will be removing some of your unsalted water with each subsequent change after the first.

I'm not trying to discredit Byron as he obviously knows a great deal about fishkeeping.

yyankeeyankeefan

i would like to hear what others are doing as well. i am so concerned about harming the fish. i am learning that lots of what i have been told is wrong. so i worry about stuff like this. i don't want to stress my fish or harm them in any way. i would like them to be as happy as possible.

Byron

This is a topic on which there has and likely will continue to be disagrement among aquarists. But if one considers the scientific data and facts--not theories, but facts--one should logically come to only one conclusion, and that is that regular use of any amount of salt in a freshwater aquarium is not a responsible practice. Now I'll give some of the scientific fact.

First, something that should be obvious to all. No freshwater fish is found permanently living in water containing any salt. There are some species in coastal waters that may spend a portion of their time in brackish water, but they have the ability to move into fresh and from the observations of ichthyologists this is confirmed. In freshwater that our fish come from, the level of salt is not even detectable, so one can intelligently conclude it is non-existant. So why would one subject fish to this? Fish health expert Dr Peter Burgess says he certainly doesn't advocate salt for permanent use: "Unless the species has a natural requirement for salt, then we should not add salt to an aquarium (or pond).

Second, using any treatment to "prevent" something is not sensible. We do not take Tylenol daily to prevent a headache. You wait until there is a health issue and then treat it appropriately. Fish are no different. The linked article and many others go into this, so enough said. I can provide many reliable sources, all of which will say that at the very least, there is no reason for regularly using salt in a freshwater aquarium, and it should only be used as a specific treatment, and with certain fish.

Third, the article from TFH that I referenced was authored by Dr. Stanley Weitzman, who quite likely has a greater understanding scientifically of our aquarium fish than anyone alive today. To dispute his findings other than with scientific evidence--which does not exist--is meaningless. And there was much more in that particular series of articles that would clearly show the scientific basis for the statements.

Fourth, it is scientific fact that salinity affects a fish's growth rate. Salinity affects how hard a fish has to "work" to maintain its physiological equilibrium--which is the complex chain of internal chemical reactions that keep the pH of its blood steady, its tissues fed, and the immune system functioning. When salinity strays outside the fish's natural range--which as noted above is zero--the fish's body must work harder and use more energy to maintain this equilibrium. Laur Muha in an article in TFH (Dec 2006) compared this to driving a car up a steep hill: it takes more energy to maintain the same speed as if you were on level ground. And she ascertained her data from several professional scientists across the US.

"Brackish and estuarine fish are able to tolerate and likely to prefer more than only slightly higher Total Dissolved Salts, or osmolarity. In nature this is coupled with increased pH from the other salts dissolved in the water: calcium and magnesium carbonates and bicarbonates prominently. These materials "buffer" the water at higher pH levels than waters lacking these ions. So in the wild these fish arose in or frequented waters with ALL these ions and more. Adding salt, NaCl, alone will not affect the pH at all. Adding marine mix will provide a situation more like that from which the fish's forebears came. So long as the levels are below those that would register on a full range hygrometer, short-term exposure will do little harm (disease treatment), but long-term exposure should be reserved for fish with the physiology to live in that situation. I suspect that part of the reason many livebearers do well in this situation is that it is also more stable than an unbuffered tank, and for many fish, stability is as important as absolute pH, GH, or KH, provided it is within a ballpark of their "natural range". While some salt will certainly not peel off a cory's armor, it is not right for the fishes' physiology. [cited from Salt | The Skeptical Aquarist

Here's an excerpt from the article I posted a few weeks back on the 10 most common myths of freshwater aquaria [Fishkeeping myths that just refuse to die | Blog | Practical Fishkeeping

The water should have some salt in it to stop diseases
Brilliant. I love this one, and it always puts me into an elitist comfort zone when it comes up.

Don’t get me wrong, salt is an amazing medication, definitely up there as one of the best. But that’s its best role, as medication. Or in my cooking, where I always use too much and end up dehydrated with shooting pains down my left arm.

Salt dose rates vary massively depending on the disease. Come to think of it, they even vary depending on the particular species of disease, with one strain of skin fluke being more tolerant than another.

If you’re using salt, then there’s a time and a place. By all means, add it when there’s a specific problem, and you know exactly what that problem is. Although I’ll wager that without a microscope you’ll never tell the difference between Gyrodactylus and Trichodina – both of which require different salt dosages.

But don’t just throw the stuff in and hope for the best. That’s the same mentality as taking a handful of prescription medications on a whim and hoping for the best. And I can tell you now that handfuls of meds don’t work. They just make you vomit blood and go blind in one eye.

On top of not doing anything, incorrect salt dosage is detrimental, and the level at which it can become a problem varies between fish species.

You might not think this possible, but fish can actually dehydrate, and it’s not pretty. Sunken-eyed Goldfish from excessive salt use are something I encounter all too frequently, often in retailers.

Worse still, some pathogens are actually helped along by a little salt. I wrote an article in May’s PFK explaining how growth of some skin flukes is actually sped up and assisted by the ‘standard’ dose rate of 3g of salt per litre.

And just as the final thought, once you’ve started to add salt, how do you know how much is in the water? Salt meters aren’t the cheapest of things, and sometimes not so accurate either.

Just pouring in and hoping for the best? Pack it in.

Yes I do hold the opinion that salt has no place in a freshwater aquarium. This opinion is based upon science and common sense, and the opposite viewpoint lacks both. If healthy fish and a stable biological system is the goal of the aquarist, the best thing to put into a freshwater aquarium every week is fresh water during a water change. This will guarantee healthy fish.

yyankeeyankeefan

i am just asking opinions, not stating that ANYONE lacks common sense, or anything of that nature. nor am i saying that either side is wrong. i am just asking to gain a better knowledge on the issue so i can do what is right for my fish. i am not saying one person is smarter or more creditable then the other. i ask because i wish to know, not because i lack common sense. i was told to add salt by the pet store, so i never thought twice. the fact that i am asking just means that i want to do what is best for my fish and to better educate myself.

Byron

Never said you were. You are asking the question, and you are entitled to answers. Another member interjected statements that implied error and I had to respond. Others reading might otherwise assume I conceeded, which I do not. I sincerely apologize if you (yyankeeyankeefan) took my last post personally. Byron.

afremont

Are you saying that I"m incorrect with my assessment of the origin of the 60ppm stress claim? It was not a point issue of the paper and it was not tested or observed by any of the authors, correct?

Personally, I don't equate a minor amount of salt to tylenol, more like soap. We don't encounter soap very much in nature, yet we all use it daily as a preventative treatment. It's also a great eye irritant.

These folks seem to think that salt helps with osmoregulation and as a preventative parasiticide:
VM86/VM007: The Use of Salt in Aquaculture
Here's some more people that think that salt helps with osmoregulation in freshwater fish:
Osmoregulation in Fish

These were just the top two results from Google, and I also have books that also say the same thing.