I have had quite a few, maybe 6 or 7, at once in a tank, because they came in as hitchikers.
As long as they all have something to eat, I think you can have many, although if you have lots and lots you may be unhappy if they eat your corraline.
They don't seem to fight with each other or anything. :lol:
1 adult pin cushion per 20 gallons or 30lbs of rock or so.
They are AMAZING algae eaters and will QUICKLY eat any and all hair, and other type of algae in your tank. When the algae is gone they could turn on the corals, or simply die.
Thanks, there is not shortage of alge for my urchin. Although I wish it would go on the back glass instead of the front as back there I do not scrape the glass and it is full of algae. I have notice that there has been some eating going on there so maybe it is content with what it has right now.
They sure do an amazing cleaning job. I am quite happy that I got an urchin as I never had much coraline algae now I have lots as when they eat it they also disperse it through the tank so this has worked out well for me anyways.
Thanks for the amount. My tank is a 25 gal so I will just keep the one.
I had 3 of the purple urchins come in as hitchhikers in my 75. Never needed snails again. They ate everything. Almost too well. I'm thinking now, that one or two would have been enough for that tank.
