About two months ago I added a flame angel and purple firefish to my tank. The tank was already stocked with a hi-fin goby, randall's shrimp goby, azure damsel, six line wrasse and maroon clown. Right after I added the flame to the tank, I noticed some white spots on him. He carried the spots for a few weeks (sometimes they would be less prevalent, but always came back), but eventually he lost his battle. Shortly after, the damsel succumbed to the same thing. About the time I lost the damsel, the maroon clown became very ill and looked about as bad as I've seen a fish look, but he kept eating, and within about a week or so he is completely back to normal. All the while, none of the other fish ever showed any signs of Ich.
I guess my main question is, can I ever introduce new fish to this tank again without removing the existing fish and treating them, then going fallow with the DT? Have the fish in the DT developed a resistance/immunity to the parasites in the tank? And knowing that the parasites need a host, but none of the fish showing any ill effects now, what are the parasites feeding on? When fish develop a resistance to Ich, will the parasite eventually die off, or is it always going to be there?
I guess my main question is, can I ever introduce new fish to this tank again without removing the existing fish and treating them, then going fallow with the DT? Have the fish in the DT developed a resistance/immunity to the parasites in the tank? And knowing that the parasites need a host, but none of the fish showing any ill effects now, what are the parasites feeding on? When fish develop a resistance to Ich, will the parasite eventually die off, or is it always going to be there?
