i just got my mbu about a week ago. it was fine but toda i noticed that the tails been rotting. i saw it but i thought it was just some sort of slime or algae growing on it. then today i spread the tail and damm.. the top proportion of the tail is red and white and slimyish. does anyone know what this is? and how to treat it? the puffer stopped eating too. so im worrying about its healthy overall.