Can someone help identify what this is?
Also the recommended actions to take care of the problem?
I would also ask for a recommendation on a pest control fish. I'm still new to the hobby and appear to have this issue of hydroids or something, and I also have seen aptasia. I have only seen one aptasia so far and glued it but I assume more will come soon. What is a good fish to help keep these pests in check? I would like a long finned ruby wrasse but I'm not sure it would fit the problem. Any recommendations are appreciated!