They've come and went in my tanks over the years. The first time I saw them I just watched them. They moved thru out the system then kind of self regulated I'm guessing. Most disappeared but I can always find some with a flash lightI've got a Fluval edge 6g nano that's been up and running about 5 weeks now. No fish, just CUC and random hitchhikers.
I noticed the first couple of d.hydroids a couple weeks ago isolated to one rock. They have since spread to most of the other rocks. Not infestation levels yet, but a good 6-7 that I can see per rock.
Researching this topic, you can find lots of conflicting information (imagine that ) about the risk or lack of risk they pose to a tank.
People say they can/will kill a tank. Others say they go away on their own if you ignore them. Some say they pose a threat to fish/corals, others disagree.
Does anyone have experience dealing with these things?
Are they a threat?
Most effective removal method?