:bounce:Hyposalinity Treatment
Warnings and Precautions
The hyposalinity treatment only treats a very limited number of ciliated parasites. The most notable in this group is Marine Ich (Cryptocaryon irritans).
A hyposalinity treatment will kill: Pods, snails, crabs, invertebrates, corals, most marine algae, most organisms growing on live rock, and Marine Ich. This is why it is most often performed in a separate, bare bottom, quarantine tank.
Do not use other treatment methods (medication or chemical) in conjuction with hyposalinity treatments without knowing it is approved by the medicine manufacturer for use specifically during a hyposalinity treatment. When fish are in a hyposaline liquid, the effects of medicines and medications are often quite different. Some medications/chemicals become lethal, IE. copper. Never use copper in conjunction with a hyposalinity treatment.
pH Control
pH is difficult to control in a hyposaline solution because at this dilution, the buffer ability of the diluted saltwater is not good. Be prepared for this, by having buffers on hand.
If you mess up and the pH has lowered considerably (more than 0.2 pH units) then raise the pH slowly -- no more than 0.10 pH units per day. A large pH change can seriously harm a fish, especially a sick one.
Actual Hyposalinity Process
Lowering Salinity
Over a period of about 24 to 48 hours lower the specific through water removal and RO/DI or distilled water additions. Watch pH and temperature of the added water so as to always match that of the water being replaced. Lower the specific gravity to a reading of 1.008 to 1.009 specific gravity units. Maintain this specific gravity through out the full treatment period.
Maintenance
If the treatment tank has an active biological filter, don't necessarily assume it's working. When the salinity is lowered the bacteria sometimes temporaily hold off in their metabolism of ammonia and nitrites. Controlling water quality and especially pH can then be a challenge. Therefore check for ammonia, nitrites, and pH twice each day at the start, until readings are zero for ammonia and nitrites. Don't count on the pH to remain steady. It must be checked at least twice a day and if needed, adjusted.
Make water changes if needed to control organics, ammonia, nitrites, nitrates, etc.
Nutrition
The fish must be offered and gotten to eat throughout the process. The best foods available must be provided.
Salinity Control
If the tank water salinity is allowed to go up, the Marine Ich parasite will not be killed. If the tank water salinity goes below the target salinity, the fish are in danger.
Treatment Time
The fish is kept in hyposalinity 4 weeks after the last spot is seen. After the last spot disappears, the hyposalinity continues for another 4 weeks. If during that 4 weeks, if any spot is seen, the time/clock starts over. There must be a minimum of 4 solid weeks with no spots seen.
Raising Salinity
The raising of the specific gravity is very stressful on fish and this part must be done slowly. It should take 6 to 7 days to return the water to its normal salinity. Raise the specific gravity by about 0.003 specific gravity units or less, per day.
When the treatment time is over, there is no need to add back distilled water to compensate for water that has daily evaporated since ending treatment. When you go to raise the salinity, add small quantities of high specific gravity than normal mixed and aged salt water.
Final Period of Treatment
After the salinity is returned to normal, hold the fish in the treatment tank for another 4 weeks to verify it is cured. Look for spots every day, very closely. Observe the fish behavior, breathing rate, flashing (scratching) and look for any other Marine Ich symptoms. At the end of this time, the fish is cured/free of Marine Ich if no other symptoms are seen.
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