I thought I'd ressureect this as there's been some more postings about Potter's Angelfish recently. I happened to find the FAMA article I was thinking of earlier up in the thread. This is from FAMA March 2008, Volume 31, #3. Bob Fenner wrote a moderately lengthy article about the species, and it really helps illuminate some of the reasons this fish doesn't do well. Personally, as beautiful as I think they are, I won't buy one.
"As mentioned previously, the majority of Potter's Angelfish collected from the wild are doomed despite anything you might be able to provide or do. They suffer from what Morgan Lidster of Inland Aquatics labels 'Post Trauma Collecting Disorder (PTCD),' or the sum total of stress and damage from and through the process of gathering, holding, and shipping wild livestock. Potter's Angelfish are suitable 'poster children' here, with most dying mysteriously at some point soon after capture."
Mr. Fenner goes on to reveal a disturbing statistic (unverified in the article, but c'mon, it's Bob Fenner...I'm sure he has a source...) in that "Somewhat less than 5% are alive within one month of capture. Most of this attrition can be traced to simple stress and damage in collection."
I wish I could reprint the entire aticle, but I think you might be able to find it online at FAMA's website. B.F. also further confirms our original suspision that this is indeed a deeper water species, although not so deep as to have any decompresion issues: most adult P.A.'s are found in 50+ feet of water. So, all in all.....maybe a species we should stay away from. I won't tell anyone to NOT buy this animal, but I would definitely hope the purchaser is ready with a proper size tank with the right amount of live rock before the fish is brought home. Hope this helps!