Okie dokie, I have compiled a second draft/recap of all the information we've gathered up on this forum about treating ich with hyposalinity. I tried to use only quotes from legitimate sources, with links where possible. If everyone who has been following along would please review this for me and make suggestions for changes or additions, that would be great!
The method I have used to successfully treat infected fish was to put them in a quarantine tank with a filter, an air-stone to prevent bacteria growth and reintroduce oxygen into the water, a tank heater, and salt water. The equipment is mostly low-cost, and you probably have it lying around already. If not, check craigslist!
Fill the tank with salt-water at 1.009 salinity. Put your fish in. You can acclimate him if you like. Lowering the salinity will not harm the fish, though raising it quickly might. Lower salinity is actually stress-reducing (see scholarly articles later in the paragraph).
Leave your fish in QT for 6 weeks. At the end of that time, if he is completely ich-free, slowly begin raising the salinity so that at the end of the 6th week it matches that of your display tank. You can do this over a period of 3 days (though I performed normal acclimation on mine within an hour with no ill effects). Then acclimate him to your display, and release him!
However, if at the end of 6 weeks in the QT, he still shows signs of ich, leave him in the QT for up to 10 weeks and be patient. The parasite will eventually cycle through its life stages and drop off, and it will die off in its free-swimming form because of the low-salinity.
Your fish has a better chance at full recovery if you nip the ich in the bud! Examine your fish every day for signs of infection or abnormal behavior (itching on rocks, faint brownish spots), especially if you've added a new fish or if your
water quality has not been up to par lately. Also, you can keep the Quarantine tank at hyposalinity and treat all of your incoming fish for ich whether its visible or not. Inverts and corals and non-bony fish are sensitive to hyposalinity, so this is a bony fish only treatment-- no live rock either, and no sand/live sand.
Here is my video demonstrating bacterial susceptibility to environmental salinity changes:
http://www.youtube.com/watch?v=ZLPOnhnbSic
Here is an article explaining how hyposalinity works to lyse the ich (There are more scholarly articles regarding which life stage is affected by hyposalinity further in the passage but this is a great general explanation):
About Hyposalinity or Osmotic Shock Therapy
A Simple, Effective, Non-Chemical Treatment for Ich
By
Stan & Debbie Hauter
/span>
What is hyposalinity?
Hypo means "lower than normal", and saline/salinity "of or containing salt", therefore hyposalinity in the simpliest of terms is a lower amount of salt contained in seawater than normal. With the salinity level of oceans and seas around the world averaging out at around 1.024 (specific gravity), although lowering the amount of salt in water by a few points might be called hyposalinity, when it comes to saltwater aquariums this means bringing the salt content down to a range of 1.013 to 1.010 (specific gravity) to be effective and truly considered as such.
How does hyposalinity effect ich and other marine organisms?
All marine creatures require freshwater just as we do to survive, they just process it differently. Since their bodies are less salty than the water surrounding them, to prevent the loss of needed freshwater they take in seawater, process it to eliminate the salt molecules, and then retain the freshwater to maintain a balance with nature. When the salinity of seawater is lowered, or hyposalinity is applied, it results in a lowering of the osmotic pressure of the water at the same time, thus the related name Osmotic Shock Therapy (OST). Fish and a few other sea creatures can withstand and adjust to this change in pressure, but protozoan (Cryptocaryon/White Spot Disease, and Brooklynella/Clownfish Disease), dinoflagellate (Oodinium/Velvet or Coral Fish Disease), and flat worm (Black Spot Disease) ich organisms cannot. Reduce this necessary pressure, particularly rapidly, and they literally explode! Although delicate corals and invertebrates may not immediately rupture as ich parasites do, these too are marine animals that cannot tolerate exposure to low osmotic pressure, resulting in a rather quick death.
When is hyposalinity most effective on ich?
Hyposalinity is largely ineffective on mature ich parasites that are well protected in the gills surrounded by thick mucus produced by an infected fish, when embedded deep in the tissues of their host, and during the final encrusted cyst stage of life. It is primarily during the free-swimming phase of life when newborn organisms are released from a mature cyst, and before they have the chance to fully attach and develop into mature parasites that they are most vulnerable and can be eliminated with hyposalinity.
When can this method of treatment be used?
Applying hyposalinity or osmotic shock therapy to treat ich problems is a personal choice decision one has to make, but here are many of the ways it can be used.
While treating fish in a QT, lowering the salinity can help prevent newborn ich organisms that might be released from mature cysts from reinfecting the fish during the quarantine period.
As a preventative measure, when new fish are brought home and placed in a QT for several weeks of observation before introducing them into the main aquarium.
For Fish-Only Tanks
(Note: Under the following situations it is recommended to at least remove and give all exposed fish a freshwater dip, preferably in combination with at least a one time appropriate medication treatment before placing the fish back into the main aquarium, at which point the salinity is lowered for 3 to 4 weeks.)When a QT is not available, or the choice is made not to treat ich infected fish in one.When one does not want to leave their aquarium empty with no fish to look at for month.
When there is concern or one wants to lessen the possibility of reinfestation occurring after the fish have been treated in a QT and returned to the main aquarium.
When reinfestation does occur after the fish have been treated and returned to the main aquarium.
41);">
Hyposalinity should NEVER be used in a reef system, as it will kill corals and all types of delicate invertebrates. Since most people in all likelihood will not want to disturb these animals, not to mention have to hassle with removing them and set up another tank to put them in, the easiest thing to do for a reef tank is to leave it devoid of all fish for at least 4 weeks and allow the ich to run its life cycle and die off.
After some research, I managed to find an article by a PhD confirming that the higher temp does speed up the cycle of marine ich, but does not kill them (unless you want to use 90-100 degrees, which also will kill fish). If you raise your QT temp to 80-85 degrees to speed up the ich cycle into dropping off, make sure you use an airstone to restore oxygen into the water. I wouldn't recommend shortening the QT time even if you use a higher temp (though some sources say 4 weeks is sufficient QT time).
About Ich's life cycle:
ily: calibri;">---In the Trophont cyst stage where the adult parasite is attached to a fish and feeding on it the time frame is 3 to 7 days. (These are the white spots on the fish, or it can be hidden in the gills and completely invisible).
---In the Trophont free swimming stage where the parasite has fallen off the fish, it looks for a place to attach its self. This stage can take up to 18hrs.
---In the Tomont stage where the parasite goes into reproductive mode while it is attached to something (like a rock) the time frame is 3 to 28 days.
---In the Theront stage where the newly hatched parasite is fee swimming and looking for a host the time frame is 24 to 48 hrs.
If we add the longest time frames of the four stages, we come up with approximately five weeks. Add one week for a margin of error and you get the reason for six weeks of quarantine.
"There are conflicting reports as to which part of the cycle at which hyposalinity kills the ich. Some say it will cause the Theront (free swimming/infective) stage to rupture, killing it. Some say it causes problems in the Tomont (encysted/reproductive) stage. Tomonts need a higher osmotic pressure to finish the reproductive cycle; at a specific gravity of 1.009 they cannot complete their part of the cycle. They die, never to emerge. Whichever the case, hyposalinity works." <-- Regarding this statement, I found that hyposalinity ruptures the trophont cysts that are on the fish (the white spots) releasing most of the swimming form of trophonts into the water. Hyposalinity also then prevents the next stage, the tomont stage, from reproducing.
/>
"There may be some concern that hyposaline conditions could be stressful to marine teleost fish, or otherwise potentially harmful. While this is true in extreme salinities, studies indicate that this is not the case in more moderate salinities that would be employed in hyposalinity therapy (Wu & Woo, 1983. Woo & Chung, 1995. McDonald & Grosell, 2006).
Natural Sea Water is much more saline than the internal fluids of marine fish. Because of this, they expend a considerable amount of energy to reduce the excessive salt load through the process of osmoregulation. The kidneys are not the primary site of electrolyte management in marine teleost fish (Stoskopf, 1993). Chloride cells in the gills excrete excess chloride and sodium. “The kidneys of marine fish do play a role in electrolyte excretion; however, there function is more important in the balance of magnesium and sulfate levels and not, as might be assumed, in sodium and chloride elimination” (Stoskopf, 1993)."
span id="yui_3_7_2_1_1368593342156_6931">
"Acclimation and alleviating the effects of stress
The effects of stress caused by capture, transport and handling is a major concern when acclimating fish, especially when they have been bagged for a prolonged period. Stress affects fish in two ways: it produces effects that disrupt or threaten homoestatic equilibrium and it induces adaptive behavioral and physiological responses (Wendelaar Bonga,1997). Osmoregulatory dysfunction is closely associated with stress in fish. This is recognized by an increase in osmolarity in saltwater species (Carmicheal et. al, 1984. Robertson et. al, 1988.). This can manifest in the loss of up to ten percent of body weight due to dehydration in one or two days (Sleet & Weber, 1982.). Reducing the salinity gradient between the water and the internal fluids of fish is effective in counteracting osmoregulatory dysfunction and other physiological responses to stress (Johnson & Metcalf, 1982. McDonald & Milligan, 1997.) With marine teleost species, this is accomplished by reducing the salinity of their environment.
Quickly acclimating recently transported, or otherwise stressed marine teleost fish to low salinity water will help them to recover normal homeostasis more rapidly. Marine fish are most sensitive to changes in temperature and pH during the acclimation period. Match these parameters in the quarantine tank closely to the shipment water, provided they are not at levels that are dangerous to the fish. Then the pH and temperature can be adjusted slowly over a couple of days to match the display aquarium."
1368593342156_6945" style="margin-bottom: 1em; font-family: tahoma, verdana, geneva, lucida, arial, helvetica, sans-serif; font-size: 12.727272033691406px; background-color: transparent; line-height: 1.75em;">
"Quarantine
Placing fish in hyposaline conditions during the quarantine period is a proactive approach to dealing with some types of external parasites. Rather than waiting for fish to exhibit signs of infection, why not be one step ahead? This can save time, improve an animals odds of survival and help protect the established livestock in the display aquarium. Hyposalinity therapy is an excellent treatment for Cryptocaryon irritans (saltwater ich). It can also be effective against some other types of parasites such as the Monogenetic trematode Neobenedenia melleni."
Also,
1.75em;">
"Hyposalinity can be employed in better acclimating recently transported fish, for quarantine, treating wounds, with antibiotics, getting fish to begin eating, conserving metabolic energy, improving growth and alleviating the effects of stress.
I am not suggesting that all marine fish be kept in hyposaline conditions indefinitely. What I am suggesting is being open to investigating the various potential applications for hyposalinity therapy."
*****I
ch can be in your tank when you can't see it-- some symptoms besides white spots are darker mucus spots on the fish, or the fish scratching against solid objects (if you see this, its in your tank, even if there are no white spots visible). This is why your fish will sometimes break out with spots when stressed. Increase in temperature does speed up the life cycle of marine ich to its vulnerable stages more quickly; but use aeration because high temps kick oxygen out of the water. Changes in temp affect specific gravity; use a refractometer or keep a close eye on salinity. Ich is vulnerable during "free-living" stages -- both theronts/tomites or protomonts. Use hyposalinity for a month or more (preferably 6 weeks) to kill off free-living stages in a fish-only environment.
Also,
"Some strains of Cryptocaryon irritans are more tolerant of low salinities than others, in which case reducing the salinity further and/or extending the period of hyposalinity may be required."
i_3_7_2_1_1368593342156_6939" style="font-size: 16px;">
"Treating Reef Aquariums
Because copper and reduced salinity regimes cannot be used to treat reef aquariums, the only completely safe way to deal with marine ich in a reef aquarium is to remove all of your saltwater fish to a hospital aquarium where they can be treated separately.
Once the reef aquarium is devoid of saltwater fish, the parasites will not be able to find hosts and will eventually die. This takes a minimum of four weeks. <--- (6-8 weeks recommended to get your DT ich-free. Treat the fish with hyposalinity while they are in QT before putting them back into the DT.)
bottom: 10px; font-weight: normal; background-color: rgb(250, 250, 250); font-size: 12px; line-height: 14px; color: rgb(29, 28, 27); font-family: Arial, Helvetica, sans-serif;">
Prevention
Because treating marine ich is not easy in aquariums containing anything other than bony fish, prevention is the best way to manage this particular disease. All new livestock should be quarantined with hyposalinity for a minimum of four weeks prior to introduction. This will provide ample time to detect, and if necessary treat, ich infections."
http://www.fishchannel.com/fish-health/saltwater-conditions/marine-ich.aspx
