Urgghhh. your questions is like a punch in my face.
- yes i share net between tanks
- yes i share the pump to drain the water for WC between tanks
- yes one of my ray is stop eating and i suspect a parasite issue as everyone else are eating like pigs
- the sick ray is the new coming ray. He was fine for the first week and suddenly stop eating 3 days ago
- i cant find prazipro here in indonesia. I think i will buy it in singapore next week but im afraid if it will be too late already
Damn!
I store my nets in a bath of methylene blue. I have begun to dunk/briefly run my water change pump in it as well.
Look around this site, there is info about yhe main drug in prazipro. You should be able to find the powder where you live and mix some yourself. I foeget, but there is an special way to mix it....more than just "add water" so read up on it.
I think/hope you have time to get the meds. If he was eating for you already atleast he has some food in him. The meds usually get em to eat in several hours/ a day in my experience.
Good luck and keep us posted.