Hello All,
I have received advice on battling ich from a lot of people here on this forum by using doses of salt. I have been seeking advice elsewhere as well since it still did not sit with me that Oscars come from the Amazonian basin - which is very soft water with very few minerals or salts in it due to the leeching effect of the river bed/bottom and it's absorbative properties - yet to battle a skin parasite we dump salt into the tank in large proportions of tonic doses.
Keep in mind that 2 of my LFS have also given me this advice about using salt and turning up the temp to battle ich (yes I am using ich meds as well). I realize there are a ton of people that have had different experiences as well as results...Then I ran across some other information which I have quoted below from another fish keeper:
"While I know this information will fall on deaf ears, I feel it is imperative, again, to make sure that correct, well researched information is available to others that may read this thread, as opposed to abiding by a Pre-WWII myth that tonic doses of salt is beneficial.
To begin with, the highest level of Nitrate (indicative of a pollution issue) ever recorded in the Amazon River, after decades of daily testing, is 1.24ppm. In the Orinoco River (where a signicant percentage of wild caught Oscars come from) it is 80ppb (virtually undetectable). So the statment of, "actually due to pollution and such those poor little fishies (wild fish) have a thicker slime coat " is simply not based in fact.
Standard aquarium salt is sodium chloride. Sodium chloride will not add to the type of hardness that results in calcium deposits on your aquarium but it does add to the overall general hardness of the water. While some fish, such as mollies, guppies, and other livebearers, may benefit from this, other fish, especially softwater fish from places such as the Amazon River basin, do not tolerate it very well. The Amazon River and its surrounding tributaries contain very little electrolytes in the water. So adding salt to the water of these fish is adding what would be considered pollution in their native environment.
But to truly understand the issues with salt you just have to review what science has informed us of the realities associated with the use of salt in freshwater aquariums. To do this you have to view the “supposed” benefits of salt usage. These are:
1. Osmoregulatory Stress Protection
2. Slime Coat increaser
3. Disease Inhibitor
Studies have identified that to improve Osmoregulatory stress protection the required dosage of salt is 1mg/l to 3mg/l. This equates to 1 teaspoon of salt (actually, sodium chloride as it is the chloride ion that performs this function) per 484 to 1,453 gallons of water. Unless you are using distilled water, or R/O water, your tap water will contain AT LEAST this concentration.
We’ve already discussed the use of salt to increase a fishes slime coat. The fact that this is unnecessary in almost all instances appears to be irrelevant to this conversation. Fish do a fantastic job of maintaining their own slime coat, adjusting its thickness as necessary to protect themselves. Salt acts as an irritant, causing the fishes slime coat to increase. But anything that is occurring to the fish to warrant increasing the slime coat will already be handled by the fishes defense system. In other words, if the fish needs its slime coat increased because of toxins or parasites, it will do it itself, as necessary, without you adding salt. If the fishes defense systems are so damaged that it can’t defend itself by increasing it’s slime coat, adding salt is not going to help because the salt will not magically result in the fish repairing its defense mechanism and suddenly increasing its slime coat. In these instances, a different mechanism must be employed by providing a synthetic polyionic or colloid coating. These are available in numerous water conditioners and commercial slime coat enhancers.
Finally, salt is identified as a disease inhibitor, which includes fungal, bacterial, and parasitic diseases. There is some truth to this, but it is not as effective as other products on the market when it comes to most diseases. It is effective at treating Ich, when used in combination with heat, but as a fungal and bacterial remedy it is limited. However, nothing associated with this has to do with use of salt as a “tonic”. Salt does aid in speeding up the healing of injured fish. It does this via hyperosmolarity. Fish, and their surround water, contain a concentration of total dissolved solids (specific gravity). If the surrounding water has a higher specific gravity than the fishes body then fluids from a wound site move into the water around it. Fresh plasma fills in the areas vacated by the fluids leaving the body, creating increased blood flow in that area, making it heal faster. But again, this has nothing to do with “tonic doses” of salt. It involves using salt to treat a specific circumstance.
Finally, the best use of salt, and one for which there are few alternatives, is the use of salt to prevent Nitrite poisoning. An article on The Skeptical Aquarist explains it best:
Quote:
During shipping, fishes' excreted ammonia can form nitrite, and the addition of enough salt to make a 1% solution has been found to cut shipping losses by as much as 90% in commercial practice. Nitrite is toxic, as you know. Fish that are stricken with nitrite poisoning get lethargic. With higher levels they may gasp as if they were suffocating and die with their gillcovers open wide. The nitrite ion has the damaging habit of occupying the place on a hemoglobin molecule where oxygen ought to be carried. The resulting molecule, called "methemoglobin" carries no oxygen. Under the influence of high NO2 levels, the fish may suffer from "brown blood" syndrome or methemoglobinemia (yeah! "Me-THEME-o-Globe-anemia").
Though the main effect of nitrite is on the oxygen-carrying component of red blood cells, it's recently been shown to suppress chloride cells in the gill lamellae, which play a major role in maintaing a balance of salts. (Download the abstract of a 2002 paper read by O.T. Ferreira da Costa and M. N. Fernandes of the University of Sao Carlos, Brazil, "Chloride cell changes induced by nitrite exposure...")
How much salt should you be adding to counteract nitrite? It is the chloride ion of salt that is effective, not the sodium ion. In order to be effective, the chloride-to-nitrite ratio should be five to one. So if nitrite tests at 1 ppm, you should add enough salt (as a temporary measure) to give a chloride level of 5 ppm. This corresponds to about 8.5 ppm of NaCl (table salt); very little--— a fifteenth of a teaspoon or just a pinch-- in ten gallons. In fact, your water quite likely already carries this much salt, without any extra dosing at all; at any rate, your normal partial water changes will dilute out additional salt after the crisis has passed.
There you have it, everything you need to know about salt, summed up in a two page forum post. Anyone reading this post has the option of following guidance identified by science or discarding this information and following a pre-WWII Myth.
The myth started because people noticed that when shipping fish, or when placing fish into new tanks, they experianced decreased mortalities (this was well before knowlege of the nitrogen cycle). We now know this was because of the ability of salt (the chloride ion) to prevent nitrite poisoning, but they attributed it to something else. That "something else" evolved into the tonic use of salt as an additive, without a factual bases in science. And in the aquarium hobby, myths die hard."
So....is there anyone here that is an actual marine biologist or associated professional that can settle the question - How much salt, if any, can be used on Oscars, both for medicinal purposes as well as in general tank maintenance?