Hypo question

[Docdiggy]

I'm thinking of doing hypo or cupramine since I noticed some ich. I am going to hold out a bit and see if it progresses. I've used cupramine in the past but, I was thinking of trying hypo. My question is, if I use a sponge that has been well seeded, will it die in low salinity? If so, how do you maintain any bacteria ?

[Dmorty217]

Hypo is the most ineffective and stressful method you can use to cure ich. Also it's the most difficult to do correctly. I would stick with cupramine since it's a proven method that works and you don't have to worry about killing nitrifying bacteria

[ThRoewer]

Hypo is the most ineffective and stressful method you can use to cure ich. Also it's the most difficult to do correctly. I would stick with cupramine since it's a proven method that works and you don't have to worry about killing nitrifying bacteria

I have to disagree with this.

Hyposalinity treatment is the easiest and least stressful for the fish. In my experience it is also very reliable and quick (3 to 6 days) to get the fish ich free. But to be sure the treatment should be at least 2 to 4 weeks.
As for hyposaline ich strains - to my knowledge these have so far only be observed in Taiwan and only on farmed food fish that were kept in brackish conditions. I somewhat doubt that this strain actually made it into aquariums as to my knowledge no reef fish are imported from Taiwan.

Maintaining the salinity is also quite easy and really just requires a good refractometer that has been calibrated with RO water (you want to be accurate on the low end of the scale). After you have adjusted the salinity in your HT just mark the water level and maintain it.

The only part of hyposalinity that might be somewhat stressful for the fish is bringing the salinity back up to normal levels. But if done slowly over the course of a week even that should be easier on the fish than most other methods to treat ich.

Hypo is for sure better than exposing your fish to an immune suppressant toxin like copper. Plus it is difficult to maintain proper copper levels in salt water so the likelihood of under-dosing is high. And if under dosed it just may mask ich but not rid the fish of it. Overdoses may damage your fish's internal organs (liver & kidney)

But Hypo, like TTM, only works against Cryptocaryon and nothing else. So a clear diagnosis is required.

Here is an abstract from Terry Bartelme's article on Cryptocaryon in the Advanced Aquarist magazine:
Hyposalinity therapy

Hyposalinity therapy has numerous advantages over copper-based medications (Bartelme, 2001c). This method does not suppress immune functions such as phagocytic activity. Antibiotics can be used in conjunction with hyposalinity therapy. Some antibiotics are more effective, or a lower dose is required when the salinity is less than that of natural seawater. The salinity only needs to be checked once a day while administrating treatment. Chemical filters such as carbon and Poly Filter™ can be used when employing hyposalinity therapy.

An accurate means for measuring the salinity is crucial when treating fish with hyposalinity. Swing-arm type hydrometers are notoriously inaccurate. A refractometer, or lab grade, large, glass hydrometer is recommended. Alkalinity and pH tend to fall in diluted saltwater. Check these parameters daily and add a buffer as necessary to maintain the pH between 8.1 and 8.3. Do not expose elasmobranches, invertebrates, live rock, or live sand to treatment with hyposalinity. This method is safe for the bacteria that perform biological filtration, at least if the salinity is not dropped too rapidly. Make two water changes per day for two days, reducing the salinity about 5ppt per water change.

Maintaining the salinity at 16ppt or less has proven to be a highly effective treatment for cryptocaryonosis (Bartelme, 2001a, b). However, this may change with if low salinity variants of Cryptocaryon irritans become common or widespread. The salinity (not to be confused with specific gravity) must be maintained consistently at 16ppt or less for the entire duration of treatment. I suggest 14ppt to allow for any fluctuations in the salinity during therapy while providing some margin for error.

Treatment should continue for a minimum of three weeks after a therapeutic salinity level has been reached. Unlike most other forms of treatment for cryptocaryonosis, hyposalinity does not target the "free-swimming" or theront stage. Hyposalinity therapy works by interrupting the life cycle at the tomont stage. Tomonts are destroyed by hyposaline conditions, thus preventing re-infection.

Teleost reef fish appear to adapt well to hyposaline conditions. Hyposalinity was also reported as an effective treatment for cryptocaryonosis by Angelo Colorni of Israel Oceanographic and Limnological Research Ltd 1985 (Colorni, 1985). A report in Drum and Croaker stated: "We now have experience that proves that a wide variety of teleosts can live quite comfortably at ½ salinity (1.010) for extended periods of up to 2 to 3 months (Goodlett & Ichinotsubo, 1997). Emperor angelfish Pomacanthus imperator were the subjects of one such study. They were kept in salinities as low as 7 ppt for 30 days without any apparent ill effects (Woo & Chung, 1995).

An alternate method of hyposalinity therapy

Treating fish with a series of short-term baths at a salinity of 8 to 10ppt will effectively destroy tomonts. This method requires a three hour treatment every third day for a total of four treatments. All tomonts exposed to a salinity of 10ppt for three hours eventually degenerated (Colorni, 1985). In the event of an infection with a low salinity variant of Cryptocaryon irritans, such as the Chiayi isolate or strain, a salinity of 8 to 10ppt will not effectively eradicate the parasite.

Handling fish every third day that are already weakened by disease may be risky (Colorni, 1985). Teleost reef fish have an internal salinity of 11 to 12ppt. It is questionable as to whether many species of teleost reef fish that can tolerate an external salinity level below that found in their internal fluids without undue stress. Theoretically, the vectors of ionic and osmotic regulatory processes must be reversed as a saltwater fish crosses the line of equal molarity (Evans, 1984). However, recent studies indicate that at least some species of marine teleost fish are capable of adapting to salinities lower than those found in their internal fluids (Woo & Chung, 1995).

source (http://www.advancedaquarist.com/2004/1/mini#section-2)