at first i thought it was just little bubbles that appeared on the fish(all damsels) because they would disappear later but then i started noticing a white haze thats when two fish died now this morning another died. what should i do? i have a 20 gal tank i can quaranteen them(5 fish left) in but what medication should i use? while in quaranteen should i run my biofilter with activated carbon?