Hello, about a little over a month ago I purchased a 5 inch male red tiger motaguense , when I got him he was very skinny and I figured it was just because of the fact that he came from the Lfs and over time he would chunk up, I keep him in a 90 gallon tank alone with the heat at about 80, water parameters are fine, anyways he hasn't grown in the slightest still looks very skinny, I give him north fin pellets for cichlids I occasionally see him come out to eat but his stomach never grows , he only eats when I'm not in front of the tank and is constantly hiding ( I figure that's normal for a parachromis of his size) anyways I'm pretty sure he has some sort of internal parasite, wondering what would be the best method of treating it ?