Well, the tank is still going, but poor Resal didn't make it. It looks like both sargassum anglers died of a bacterial infection (dropsy). I wasn't around when the first one died, but looking back, he probably had it too. I suppose we didn't give the tank long enough time between the two fish. I recall reading somewhere that the anglers are somewhat susceptible to that condition, so we've decided to take a long break from them before trying again. Up until a few days before they died, the were both eating well (frozen silversides), and the water parameters were always in check. They coral and inverts (snails, conches) were fine before and after.
That said, both were easy to get on frozen food. After about a week of feeding them ghost shrimp, they happily seemed to take frozen silverside off a bamboo skewer. It wasn't long that they both started 'attacking' the bamboo skewer out of excitement. I was worried about getting them on frozen food, but it was very easy.
Super cool fish with great personalities.