That depends on what is stressing your fish. If the water parameters are off, you should do a water change. If the fish is sick, you should work to figure out what the illness is and how to treat it. If something in the room is bothering your fish, put a blanket over the tank. Stress comes from a lot of different areas. You need to figure out what is stressing your fish in order to treat the stress.
My fish isn't stress anymore. But I may have another problem. The colour of my other betta fish will turn white-ish in a bright room. When I put him in a dark place, its colour will turn back to normal. Or maybe I'm wrong here.
In nature betta live in swamp areas with lots of surface plants. They generally don't like a bright light right over their heads, it makes them feel like predators like birds will see them easily. Your fish may be more sensitive to this than other fish, fish are all different and some are more high strung than others. Posted via Mobile Device