i have a 10 gallon tank and unknowingly purchased a dragon goby a while back, and currently have it and 2 gouramis in the tank. yes, i realize the dragon needs brackish water and will be way too big for my tank, but he has nowhere to go. im most likely getting a 30 gallon soon, but for now should i change my water to brackish to make the dragon happy, or will this irritate the gouramis?