I must interject here, the old way of adding salt is not a good idea. Sure it may have worked for some but in the end you are opening up a can on all of your fish. It is a bit long but please read. Yes I am talking about ICK in the first part, but regardless of the issues the concept of adding salt is the same.
In the last 10 years the expansion as discovered by the University of Florida and University of Georgia Ich strains that have now even become more common and will survive past 93 degrees F with only the mass amounts of reproduction happening. I would always, always, always Opt for a treatment that is the LEAST invasive least potential for other issues. Using heat and salt or just one or the other can have many of its own risks. This is why I recommend Keep temps at a normal range of 79 to 80F and use a quality proper treatment. Why? Because the use of Heat as mentioned above in not 100% a guarantee it will cure as resistant strains have become more common over the years. Also higher heat promotes a even higher loss of dissolved Oxygen that no matter how much agitation you add to the tank it cannot hold anymore O2. Ich works by means of suffocation by starving the fish for Oxygen due to pulling valuable cells of blood and fluids carrying Oxygen rich supply to the fish. The first place for attack by ich is the gills In response to this the fish cause a thickening and swelling of the gill tissue, This reduces Oxygen even further. Now we have a double hit with Ich causing reduced blood stream O2 and fish causing reduced Oxygen intake as a defense of protecting the gill tissue. Next issue of concern with this is eventually the fish can have a separation of the outer layer of the gill tissue and thus the loss of valuable fluids containing O2 into the system as further defense mechanism against ich. Again, adding salt depletes dissolved O2 and increasing temps will cause the rapid degassing of the water with no real way to actually hold more O2. The next issues are many species are not capable to handle these intense heat and lack of oxygen. While in some places water temps can rise specific fish have adapted like Discus at 86 degrees but not all and in fact not most can deal with it for sustained times. Next is the thriving of bacterial issues far more badly then Ich will ever be. The higher heat promotes the bacterial infections to thrive and secondary infections are quite common. Many of them will make you wish you had ich again.. Using proper treatments with antibacterial active agents that also affect Ich are a better preventative against these issues arising as a secondary while easier at killing ich. I can list probably more than a few bunches of fish that cannot deal with higher temps. Really when it breaks down to it. While heat has been able to work.. (btw it doesn't Kill ich it sterilizes the reproduction cycle at temps at certain level.. But even that is now shot down as resistant strains reproduce well above 93f) But the stress factors involved in the use of heat rated treatments Cause higher spiked levels of cortisol's in the body. Reduced uptake of ions and cautions for proper redox potential as the blockers in the blood stream push the immune response to its limits. I will always, always recommend using a proper medication treatment for ich where its available due to the lower stressors and effects on the fish its environment and the potentials for other issues that are far worse.
A little about Sodium chloride. In chemistry salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cat ions basically positively charged ions and anions that are negative ions so that the product is electrically neutral [This is the Dictionary and chemistry definition of “Salt chemistry”]. There are mineral salts for most minerals. But for the purpose of this discussion we are dealing solely with common salt what we know as table salt or rock salt or aquarium salt. This salt is a mineral that is composed primarily of sodium chloride NaCl a chemical compound belonging to the larger class of ionic salts. It is essential for animal life in small quantities yes. But it is harmful to animals and plants in excess. Marine salt has other minerals in it too but it is still salt for the purpose of this discussion. Salt is an irritant, which causes the fish to secrete more mucus particularly in the gills where osmoregulation is occurring. And if salt is not pre-dissolved carefully it can give fish bad burns this is especially true for scale less fish such as loaches many catfish and some types of eels and other sensitive fish. Salt makes the water denser than the same water without salt. The aquarium contains water. The bodies of fish and plant leaves also contain water, just as we humans do. We are approximately 70% water. The water in the aquarium and the water in the fish/plant are separated by a semi-permeable layer which is the cell. Water can and continually does pass through this cell. Fresh water fish do not drink because they don’t have to in order to take in water. When either body of water is more dense then the other less-dense body of water, water will pass through the membrane to equalize the water on both sides. The fish must control this process through what is termed osmoregulation. This is where the salt creates issues in this function. Fish burn much of their energy trying to regulate Osmotic function. It’s different for Salt water fish as they are constantly drinking the water.
Something’s to understand about freshwater Fish Physiology. Salt definitely interferes with the osmotic regulation of fish and plants. It should be left alone. Nature regulated that part itself, by creating freshwater, brackish and saltwater fish. The vast majority of freshwater fish live in waters having no measurable salinity and this has been crucial in the evolution of their physiology. Fresh water fish differ physiologically from salt water fish in several respects: their gills must be able to diffuse dissolved gasses while keeping the salts in the body fluids inside their scales reduce water diffusion through the skin and they also have well developed kidneys to reclaim salts from body fluids before excretion. Freshwater fish have physiological mechanisms that permit them to concentrate salts within their bodies in a salt-deficient environment marine fish on the other hand, excrete excess salts in a hypertonic environment. Fish that live in both environments retain both mechanisms. Freshwater fish concentrate salts to compensate for their low salinity environment. They produce very diluted but copious urine of up to a third of their body weight each day to rid themselves of excess water, while conducting active uptake of ions at the gills. The kidneys of freshwater fish have two functions osmoregulation and hematopoiesis, which is the formation of blood cellular components. Each fish species is adapted to the range of salts in its habitat water, and the kidneys function well within that range. The kidneys have to work harder whenever the salt content of the water in which the fish is living is greater than that of the fish’s preference, i.e. the natural habitat. The closer the water is to the species requirements the easier it will be for the fish to maintain proper osmotic levels. One of the myths about the benefit of regular addition of salt is that it allegedly maintains an osmoregulatory balance, in point of fact regular use of salt has the exact opposite effect and can cause bloating due to an osmotic imbalance. Another Myth is that salt is good for the fish to gain slime coat. While the fish does gain in slime coat its only due to a response to an irritation, a stressor that causes the fish to go into a protection mode to create higher slime levels. This is stress to the fish not beneficial.
Osmoregulation is the technical term for the physiological mechanism fish use to control the amount of salt and water in their bodily fluids. As the name suggests it's based on osmosis. Water is constantly passing through the cells of freshwater fish by osmosis in an attempt to equate the water inside the fish with the water in the aquarium. Freshwater fish regularly excrete this water through respiration and urination the average fish will urinate 30% of its body mass every day. The more salt in the aquarium water, the greater the strain on the fish's kidneys, which in turn adds to the fish's stress in attempting to maintain their internal stability. And salinity affects the amount of energy the fish must spend to maintain the physiological equilibrium the complex chain of internal chemical reactions that keep the pH of the fish’s blood steady its tissues fed and the immune system functioning. When salinity increases beyond what the fish is designed by nature to handle the fish must work harder and use more energy just to keep going. Laura Muha likens this to driving a car up a steep hill it takes more energy aka fuel to maintain the same speed as driving on level ground, and it causes more wear and tear. This increased energy output is wearing down the fish and the fish is not able to expend this crucial energy on other important functions. The growth rate is affected a shorter lifespan will usually result and there will be increased risk of various health problems along the way. BTW if you’re curious Laura Muha (that I referenced) is a renowned science writer in the biology of fish and does so for publications as such as Tropical Fish Hobbyist Magazine and other renowned writings.
Just some additional info for people about what most know as salt Sodium Chloride. Aka Table salt, Rock salt, Kosher salt, Regular salt, Aquarium Salt. It is a chemical. Many think it’s natural. And while it comes from mother earth. It is still listed as a chemical. Much like many other chemicals Like Hydrogen peroxide. Nothing more than H20 =Water and O2 oxygen. The thing to remember about Sodium Chloride is that fresh water fish spend their entire life burning much energy trying to remove fluid and Sodium from their bodies. This is the function of osmosis. By adding more sodium chloride you have now made the fish work even harder to keep osmotic balance. This can cause issues with higher salt exposure that decreases the fishes Immune system. It can cause issues with cortisols being out of balance. also note that Adding salt to the water ALSO decreases dissolved O2 levels as it becomes a dissolved solid in the water displacing the O2 and this is why Salt water has less dissolved O2 then Fresh water. Salt was a cure thought up by the aquaculture industry for fish farming for food. Where the longevity of the fishes life only matters enough to get them fat to harvest. Not like we keep fish in any way.
