pea puffers are freshwater so im guessing your talking about aquarium salt, not marine salt. i believe its something like 1 tablespoon per gallon or something of that nature, directions for dosage is on the back. temp and parameters are the same as pretty much all tropical freshwater fish. temp around 78-82 you want your ph to be 7 and try to keep your nitrites and ammonia at 0 ppm, nitrates you can have trace amounts of but i believe puffers are more sensitive to any bad parameters than most fish due to them not having scales. not sure if anyone linked you to the puffer pedia page for these guys, but here it is: http://www.**************.com/forum/ug.php/v/PufferPedia/Freshwater/C_Travancoricus/
check it out, google "pea puffers/dwarf puffers/pygmy puffers and see what success stories/unsuccessful stories you can find. even searching the website threads for pea puffers to see what people say about these guys