I have some lampeyes that are supposed to be a brackish water species, but there's apparently at least one population that has been found in fresh water. I tried to drip acclimate my fish to more brackish water over a day, but they don't seem to tolerate it really well. When I approach a tablespoon of marine salt per gallon, they become less interested in food, their lower GI tract turns red, and they aren't as interested in fighting/breeding. They perked up a lot when I did a big water change. Since this species is supposed to have longer lifespans and breed more easily in brackish water, I'm wondering how I tell whether I acclimated too quickly vs. these are just a freshwater population? Anybody have any ideas?