just change the water once no need change everytime.....add anti-chlorine and anti-stree (AZOO aqua guard)....don feed...if got heater put in on to 32deg cel.....it will be soon if not serious...

u keep changing water will make it even worst...diff water temp everytime....water ph also keep chaning...how the fella wan recover ?

this looks more like water condition problem...just don change everyday...go get japanese yellow powder....add 1 tea spoon...