my eldest male (one almost two years old) has been acting off for about a week since i did his last water change. He is in a gallon bowl that is unfiltered and unheated. I used tap water with the water declor. he has been laying on his side some days but still eats his pellets and breathes normally. i don't want to move him to a larger tank to get a heater till he shows more improvement. I moved him to the warmest room in the house so he can get a bit warmer. My LPS gave me half a teaspoon (if that) of salt for the bowl. he has perked up since i put it in and i wanted to know how often i can treat him with it.