There is absolutely no reason to add "tonic" salt to a FW tank! Many fish (like plecos, tetras & other softwater fish), will actually be bothered by it long-term.
http://www.theaquariumwiki.com/The_Salt_of_the_Earth
You're going to have to set up a separate tank for your BW fish. I'm not sure what species your silver sharks are. it is possible they might be Columbian sharks (Hexanematichthys seemanni). If they are, then they are also BW fish & can follow the GSP into SW. They also grow to 18".
You can cycle the new tank quickly or try a fishless cycle within a week-10days;
http://www.**************.com/forum/library/category/water-filtration/
Here is info on your puffer:
http://www.**************.com/forum...cus/an-introduction-to-green-spotted-puffers/
He won't be acting nice to your other fish for long...
http://www.theaquariumwiki.com/The_Salt_of_the_Earth
You're going to have to set up a separate tank for your BW fish. I'm not sure what species your silver sharks are. it is possible they might be Columbian sharks (Hexanematichthys seemanni). If they are, then they are also BW fish & can follow the GSP into SW. They also grow to 18".
You can cycle the new tank quickly or try a fishless cycle within a week-10days;
http://www.**************.com/forum/library/category/water-filtration/
Here is info on your puffer:
http://www.**************.com/forum...cus/an-introduction-to-green-spotted-puffers/
He won't be acting nice to your other fish for long...