so i got a 20 long with a 2-3 inch GSP puffer in it (do start about tank size needed and what not. he is small so for now this tank will work, i will upgrade him when he needs it) its freshwater right now. but i want to start changing it to brackish, the thing is idk how much sea salt i need to use to get it done. i have a 1gal tank i can mix the water and salt in. but idk how much, also my GSP looks to have ick on him to and thats why i want to move him to brachish ASAP. i also made a video u can see my puffer in and what im talking about in this post.