Hello,
It has been shown that doing a hypo salinity will also stress and kill the velvet but it can also stress the fish because your dropping the salinity so much. It’s been noted that dropping the salinity from 1.025 by 10 can cause it to drop off. Yet with that said it has not been verified, but can help kill it when In conjunction with the copper treatment. Remember this qt process simply does one thing and that is to kill the parasites on the fish and heal the fish. Sadly even after you do all of this, it won’t stop another infection and or outbreak. It is not verified if 76 days plus or minus is a current fallow period. Most use this as a fallow period but different strains are different beasts. Ideally the qt is to prevent it from hitting the main display tank. Where there is an outbreak in the qt it can be monitored, and then moved to a separate qt and monitored then placed back into the display. Cross contamination is your worst fear when fighting this, because simply wet hands, net, drop can start the process all over. I would also suggest get some kind of uv and even slow the dwell time down longer. Worse case you can use hydroperioxide but I need to find the dosage. It’s 20% per water volume, so for an example my tank is 240 but minus displacement you 200 but according to sources:
“Hydrogen peroxide is also FDA-approved for use in food fish as Perox-Aid, a 35% hydrogen peroxide solu- tion. Montgomery-Brock et al. (2000) described the use of 35% hydrogen peroxide to treat mullet (Mugil cephalus) fry infested with Amyloodinium. Fish in a flow-through seawater system were treated once with 25 mg/L hydro- gen peroxide for 30 minutes. Mortalities decreased from 200 to 1,000 fish per day to fewer than 10 per day within 3 days of treatment. The authors present data only for
the first 4 days following treatment. Repeated treat- ments would be necessary under most culture conditions. Removing tomonts following treatment might be an important strategy when using this method (Noga, 2010).”
“Thus, the effectiveness of using fresh water may depend upon the particular isolate of Amyloodinium. For most isolates that affect stenohaline marine fish (such as most tropical reef species), reducing salinity to < 10 ppt will usually be sufficient, but fish must be kept at this low salinity for at least 2 to 3 weeks. This strategy may not be as efficacious in euryhaline fish from estuarine environ- ments. While not yet verified, it is possible that trophonts remaining on the fish may survive the hyposalinity treatment and may be able to resume their life cycle when environmental conditions became more favorable”. (Demper 2005).
