There are many brackish fish that I just love, such as gobies, puffers, eels, etc. And I would be happy to keep these guys. So I had a question about what their water needs are. Granted brackish water is part marine water, however I have often read to add '1 teaspoon of salt per gallon' in order to meet the fishes' needs. So, do fish who inhabit 'light brackish' enviornments NEED synthetic sea salt (Ex. Instant Ocean) or would they be fine with some more normal aquarium salt?