Ich and Acanthurus tangs - Years of experience and ich management Alright folks, I wanted to share some pretty shameful realities about my past and dealing with Acanthurus tangs. To anyone that doesn't know, common Acanthurus tangs include Powder Blue, Powder Brown, Goldrim/white cheek, Achilles, Sohal, Clown, Carribean Blue, Orange Shoulder, Chocolate, and many less common tangs. Photo of Orange Shoulder Tang by R2R member @RZ5T I managed ich in my systems for years and killed perhaps 20-30% of my NON-Acanthurus tangs because they could not build up resistance to ich. Zebrasoma tangs, SOME naso, and some hippo tangs eventually seemed to thrive in systems with ich present on occasion (this is known as ich management). I've unfortunately witnessed dozens of Achilles and PBT entered in to systems with ich (but whose residents had zero symptoms and you would never know ich was present except that it may affect new additions) that within days to a few weeks were very badly affected and eventually succumbed. Photo of Powder Blue Tang by R2R member @ChristopherKriens I had a couple short term wins though - an Achilles bought from another hobbyist lived for about a year with ich with few symptoms but occasionally would get minor (but noticeable) breakouts. Eventually, it succumbed like the rest. I feel like a terrible person for being so hard headed, but I probably lost 10 Achilles tangs to ich (or removed them and treated them then tried again until they died) and probably 20 PBT. I could not for the life of me understand why they would not live managing ich as all of my other genus of tangs had for YEARS. I would change something (new skimmer, better skimmer, two skimmers, more flow, lots of macro algae, etc) that I thought would help and try again with no success. It was very frustrating and evil. Now, I can keep 90% of PBT and 100% of my Achilles tangs alive long enough to sell or keep SINCE treating them in copper. This makes me feel even worse. The PBTs I did lose since came very emaciated and had little chance upon arrival. I also killed probably 3 powder brown tangs the same way, and 6 clown tangs. This is horrible to recall. I had Caribbean blue tangs live up to 2 months managing ich but eventually died, and one that when treated properly I sold to a friend in good health. Photo of Caribbean blue tang by R2R member @Luisra This all was over the course of 12 years but honestly that doesn't make it a lot better. The reality is that 99% of my efforts trying to manage ich (and not quarantining properly) failed with acanthurus tangs. 100% if you take in to account that 1 year alive is absolutely NOT a success with a fish. I am telling you all this so that you do not continue to kill them as I did. Don't be as bullheaded. I am not proud of my Acanthurus tang massacre history but I am at least hoping that I can prevent future loss by telling the stories. Those of you that don't qt - 99% of you have ich in your system. If you've ever seen a fish with ich in your system and have not removed all fish, treated them properly, and ran the tank fallow for 9-10 weeks, with almost certainty you have ich. With some marine species, you can do that successfully long-term. Not Acanthurus tangs. There may be a rare exception, but why kill fish unnecessarily? Photo of Achilles Tang in Quarantine by R2R member @A_CoupleClowns I had lots of success with Zebrasoma tangs. The larger the hardier they were with regards to building up resistances to ich. That said, I still don't believe that doing that is moral, ethical, or good fish husbandry. So what happens when you try to manage ich with an Acanthurus tang? Let me speak from experience watching dozens suffer before I could catch them (always too late) to treat: The parasite slowly increases its presence on the fish. Starts on the gills out of sight, then on to fins, then all over the head and perhaps other areas. They increase in numbers. Simultaneously the gills become more and more damaged and the fish is increasingly less able to breathe and very slowly suffocates over weeks. The fish can be fat in the belly but it's lateral line and bones will begin to show. The parasite literally sucks the nourishment and life out of the fish. A morbidly obese tang in the belly region will eventually appear emaciated throughout the rest of its body as it suffers more and more. They will scratch, breathe heavy, lose color, swim sporadically which fades to hiding and becoming less active. They will eventually stop eating, and the parasite will finally suck the remaining hint of life out of them. If well fed and fat (lots of nori) the process can take 2-6 weeks before killing it off. It is horrible to watch, I somehow justified it by claiming the fish was weak and would have died anyway. The above experiences largely negate that. It's awful to watch them suffer this way on a glim hope that I will magically start warding them off. With my success over the past few years with these fish I can't believe I used to have trouble before. This is so much easier and more rewarding (treating all fish and properly quarantining). I've seen this process happen to hippo tangs that even disappeared for a few days only to emerge apparently ich free. I guess I expected this to happen with Acanthurus tangs. I assure you, it will not. If you cannot afford to qt, or don't have the space, or don't want to deal with the trouble, then do the oceans a favor and either stick to only the hardiest species (some of which you will still kill) or perhaps leave the hobby. It's our responsibility to these fish to keep them healthy.