OG, I've never used goldies, would guppies fall into the same class as goldies. They seem to me being a tropical fish to be more like natural prey, and as I have said, I would only feed them as a treat and not regular diet. The rare exception would be those few fish that only eat live prey, and even then, variety and nutrified feeders would be in order. I am not argueing that feeders should be a staple diet for predatory fish, I am just curios why someone would try to alter natural feeding instincts, to avoid feeding feeders. I have never been an advocate of feeding FW feeders to SW fish, I know a lot of people do it but it seems unnatural to me. I have a couple of friends who feed guppies to their lionfish and groupers, but not as an exclusive food source.