Tips/info on breeding black Damsels

[pt109]

I've noticed a couple strings of what appear to be eggs wrapped around a button polyp colony in my tank. The only pair of fish are black damsels (neopomacentrus cyanomos). I've kept this 72G tank for about 5 years now, first as a FOWLR, then converted it to a reef tank in the last year. The larger fish (female?) has been guarding the eggs for about three days. The other fish include a yellow tang, red hawk, clarkii clown.
Any info, suggestions on how to proceed would be welcome. Thx.