Feeding Twinspot Goby (Signigobius biocellatus)

[Blue Ram]

Without doing my research first I purchased a twinspot goby 4 days ago. This fish is on the "leave in the ocean list", however I learned this too late. Has anyone had any success in keeping them. From what I've read, the key is to have them eating. Not having a refugium, I probably don't have an adequate food source for them. I've read that I can buy "copepods" to add to my main tank. Any advice and/or suggestions would be greatly appreciated.