So the general concensus is that Blackworms are way cool, but tubifex, not so much. Which I interpret as to mean that some folks love tubifex and some are afraid of them, except for African herbivores, where the results will for sure be fatal. Since I started this string, I thank you all for your plentiful responses. I guess I will try to get blackworms. If I get into the smaller killies, I will probably have to try to get some tubifex again, as I have seen some killies have trouble getting the blacks into their tiny little gullets. Speaking of tiny, will Apistos as small as 3/4" be able to get eat blackworms whole, or do I need to chop them up? Bob