Theroetically at 1.009 it cn destroy ich. But it doesn't always and you can't go lower becaue teh fish can't deal wit hsg lower than it's internal sg of 1.008. It is a valid treatment option for marine ich but not always realiable and it requires a long stay isn QT.
Fish are often shipped in low sg water . It makes them drink less and process less urine .It can old more oxygen and has relatively low ph which helps detoxify ammonia in he bag. I can see why an lfs might hold them in lower sg since it more like the water they are shipped in and saves some salt but ich treatment at 1.015 won't kill ich.
I agree lower sg helps with oxygen which helps ammonia reducing bacteria and reduces the metabolism but I don't agree it is helpful long term since the fish has evolved to live in the sea with an avrage sg of 1.0264 except for brackish species of course. Long term atrophy of some organs appears likely.
Fish are often shipped in low sg water . It makes them drink less and process less urine .It can old more oxygen and has relatively low ph which helps detoxify ammonia in he bag. I can see why an lfs might hold them in lower sg since it more like the water they are shipped in and saves some salt but ich treatment at 1.015 won't kill ich.
I agree lower sg helps with oxygen which helps ammonia reducing bacteria and reduces the metabolism but I don't agree it is helpful long term since the fish has evolved to live in the sea with an avrage sg of 1.0264 except for brackish species of course. Long term atrophy of some organs appears likely.