I just got my first pair of young clownfish. One percula clownfish, one ocellaris. Both are under 2 inches. They are the only fish in my 55 gallon tank, newly cycled. I've had them for 2 days. They don't seem very hungry when I feed them. I've noticed that the percula has long white stringy feces. Today (day 3) they also seem less active. I think it might be internal parasites. What is the best medication to use, and how do you recommend administration?