do you have fish only? or reef tank with inverts, becuase reef tank with inverts should be around 1.025-1.026 and fish only , you can get away with 1.022-1.024 You need to remove some salt water and replace with ro/di water,, slowly maybe a gallon a day.. depending on tank size... obviously if you tank salinity is LOW you replace the evaporated water with salt water.. hope this helps.