Tank transfer treatment

Well, never had SW fish, but 'best practice' imo is always to quarantine FW fish first. Some people simply observe the fish for a length of time depending on temperature while also using other treatments. If no ich or flashing is observed over a long enough period, it's assumed no ich is present.

I prefer to raise the temp of the quarantine tank at some point to ensure as much as possible that ich is removed as observation is less certain.

Since I don't know the marine ich biology at all, I have to simply say that it's feasible to handle FW fish for ich using heat over a relatively short period of time. The method as it's described here http://www.reefnation.com/tank-transfer-cs-marine-ich-cryptocaron-irritans/ seems to have one issue for FW fish and that is that the water that FW fish come in may already contain cysts so there is no certainty that the only parasites after x days, are the cysts just hatched off the fish.

Since it's my guess that marine ich has a much slower life cycle and that most marine fish can't handle the same level of heat that most FW can, heat is a quick and solid method for FW fish, that I'd guess is not available to SW hobbyists. It's quite clever and ingenious for SW fish.

http://www.metapathogen.com/ich/

At 25C (77F), the cysts that drop of FW fish will hatch in 18 hours. Unless you plan to drop temps even further than 77F, you will need to move the fish every 18 hours (faster to be safe), not every few days. At lower temps, it will take longer to hatch, but lower temps for tropical FW fish are not recommended much below 77F.

I assume that the method works for SW fish because the parasitic cyst stage takes a much longer time to gestate into free swimming parasites in temps normally found with SW fish.


If you have FW fish that can not handle high temps or low amounts of salinity, there are chemical treatments that can be an alternative. Technically, this method will work as well if say, you drop the temp to 74-75F, then move the fish every 12-14 hours, but I think the stress of the lower temps and constant movement may not be a good alternative.

Of course, the best practice is to avoid introducing ich to the tank in the first place. A proper quarantine (or sterilization) for all water, fish, other animals and plants should be given before introduction to the main tank. But this does provide a potential solution for FW fish that can handle lower temperatures and will not be unduly stressed by daily moves.