sea urchin safe??

[antwon]

hi i just recently bought a long spined sea urchin to control my algae. however, my lionfish tends to stay near it because the urchin is in the area of his tank. he has already touched the spines. shud i b worried that the urchin will prick my lion and kill him?

 

[flower]

 
I'm not sure about the lionfsh, most fish figure out real fast what to leave alone. However..you need a very well established tank for that type of urchin, it will gobble up every drop of algae and then starve.
 
They even feed on coraline algae. If the coraline is thick enough it won't take it down to bare rock, and if you have enough algae it will graze clean one side of the tank and then move to another and hopefully the algae will grow back fast enough to keep it fed. At least that was my plan. So far so good.

 

[ryancw01]

They are not venomous at all so you have nothing to worry about with the Lionfish. Flower is correct about the urchin though. They will eat all your coraline algae pretty quickly. In some cases they will ignore the hair algae and go straight for the coraline instead.

 

[saxman]

IME, Diadema sp. are one of the best algae eaters, and the only readily available urchin that is close to being a true vegetarian. They tend to go for nuisance algae first, then they'll start on coralline. However, they often graze right down to the LR and as such, do make an impact on the coralline growth. They get large, and are a real PITA to move once they get some size on them, but they're great urchins.
 
JME

 

[wangotango]

They should be fine. The lion should know enough to stay away.
 
Make sure all of your corals are epoxied to the rock. Diadema are bulldozers....

 

[mrdc]

I warned my buddy about them but he went ahead and got one. Now he complains how it constantly knocks over coral and how they attach themselves so hard to the rocks.