aquarium health

I found these two worm looking parasites or bacteria? Was wondering if these are harmful to my tank or beneficial. I’ve never seen them before. Anyone know what they are. One was found in my carbon reactor, and the other was found in my main tank.

Hi everyone, I am in need of some help with my reef tank again. I was on here last month with a cyano issue that has now been pretty much-resolved thanks to the help of the users of this website. I have another issue that I am now tackling and am having some trouble with. After clearing green...