Yes there are a lot! They are rather small. I think because I zoomed in they look big. I really don't know if they are really copepods due to the number of them. And what puzzled me is that I had a problem with nitrates for a while yet, they kept multiplying. I tried feeding them marine algae/seaweed that I usually feed my tang and they seem to love it.
Thats not my stump tank. It's actually quite a big container with holes where I isolate my reef lobster. I bought him on a whim and he really does look very cool but he doesn't come out from below the rocks so I decided to catch him out. MY DT has two maroon clowns, a fairy wrasse and a blue tang.