Accidental population of copepods?

[Kelsey Fletcher]

Ok so my 55 is well over a year in age and about 2 months ago I was looking at my live rock and noticed that I had literally thousands of copepods on my rock. Now, the strange part is I have never put a copepod in my tank. Ever. Could I have gotten it from water from when I bought a fish and there were copepods in that water and it somehow got into the tank? it still confuses me to this day and was wondering if its ever happened to anyone else!?

 

[KrisReef]

I've had hitchhikers before, including microfauna (shrimps) that I've added somehow? I always figured that they came on a live rock.