MEDICATION

Today is day 10 of medacation for my discus one of them was going black and letting the others peck his side. I was told this was parasites so i have been treating with sterazin course finishes today the effected fish seems better now he/she is eating better aswell also have been treating for worms just incase. Now going to do 50% water change. Well did water change and found the nitrate is still 40ppm so doing another one tomorrow. I think i might put 6 of the smaller fish in the other tank tomorrow as it is now stable PH6.9 KH4 GH7 All looking good.