Hmmm, how long does it take to multiply? Is it a good sign that this guy is coming out of the woodwork now? My tank has only been set up for a week or so, so hoping this means is getting balanced.
Shall I leave him for a little while, a week or so, and then take him out?
I had hundreds in my tank. I had to buy a harlequin shrimp after a while because they would be on a zoo, and when they got off it, it was gone. Yes in my experience they do eat zoos. I would get it out now.
Most are harmless. They won't multuply unless they have what they need to eat and usually that is algae. Some have reported problems but for most of us they cause no problems.