I have a discus with what looks like white string poop. I have been told it a parisite and to treat with metro and some other meds. I have also been told it constipation because there seems to be gas bubbles in the poop that's hangin before it falls. He also is not eat much and his color has gonna dark. What do i do .......... his belly is not bloated, so not sure why it would be constipation. There is also other fish in the tank and there all looking fine even other discus. i was gonna do a salt treament on him to see if it helps but not sure how much salt to use and treatment time in the salt