"Patty-cake, Patty-cake . . . " (>__<)
You better put two exceptions in there....Here is my 120G FOWLR. It is one of six tanks that I have set up. I have 53 fish right now and no idea how many corals and inverts. 5 years ago I stopped all dry food and went to a fresh, frozen, and live diet and started a AWC system. Right after I lost a tank to disease. The majority of the fishes diet is homemade blender mush followed by live black worms and white worms. My 2 reef tanks get daily doses of BBS and I also feed live gut loaded brine shrimp on a somewhat regular basis. I also pull a handfull of caulerpa and/or cheato from the sump everyday and feed it to the fish. This tank was started a year ago this week. It was cycled in 12 days and the first two fish in were the Foxface and Dragon Wrasse which outgrew my other tanks. The PBT went in around last April. It was in a QT tank for 5 days because the SG was 1.013 from the LFS and got one dose of Prazi. The last fish in was the Golden Hawkfish which is in the upper right hand corner. He had a dose of Prazi in the bag from the LFS and no QT. There is also a GHS and a Blue Headed Tilefish in the tank. There have been new fish that showed spots of Ich over the years but they go away quickly and I have never had a problem. I do have a QT that has a couple of full time residents in there, a Chinstrap Jawfish and a Red Tail Butterfly. These two guys have seen over 25 fish, mostly the ones from on-line stores and for about 3-5 days, go through their tank including the ones with ich and have never been sick. I believe this can be done with good water quality, good diet, and good basic husbandry skills.
As someone that's watched these forums and others for years and had dozens of attempts myself, husbandry can be exemplary and it's reckless for me to suggest that this can be repeated, even by you a second time. Literally 100 others will have died in the same scenario. Although it sounds like you have great husbandry skills, and I commend you for that, 8 months though is far from a success. They should live a decade or more. I assure you that won't happen with that one. I too have kept a couple for up to a year and know of another that did for two years.
I respectfully disagree that it can be repeated to a degree statistically relevant, but again commend you on your husbandry.
OK, that was the FOWLR with the PBT. Here is my 120G reef with a Purple Tang that I have had for over two years. Right hand side. Sorry for the bad photo. It showed ich right after I purchased him and then it was gone 2 weeks later. Maybe I should have included this in the first post. But most people seem to center in on the PBT as being more diffilcult than a Purple. My bad.
I've managed ich with zebrasoma tangs for years it's not that hard for most of them except that these days velvet is everywhere, no tang can live with that for even a year in such a small closed system.
This is why I struggled so hard with acanthurus tangs, I couldn't wrap my head around why they were so different.
Separate names with a comma.