Help with picking an urchin

[Paaxil]

I want an urchin. First of all because they are incredibly interesting critters and second, I need to get rid of the mass of hair algae on my back wall and red bubble algae that I have everywhere that no one seems to enjoy eating. Any info on urchins that people have would be wonderful whether they enjoyed the pet or if it became a total nuisance. Oh, and I will put this guy in my 20 gallon so something small like a short spined, tuxedo, or pencil urchin. Any input is helpfull!

[rhiggsbear]

Do you muck live rock? If so, they will grind the coralline algae off and knock over your rocks.

[woodiecrafts]

As long as your rock work is solid, a tuxedo urchin would be flashy choice. I would think a 20 gal would be large enough for one, but they like alot of rock work to hide and dwell in, hence the reason for it to be fairly solid. Loose rocks tend to get knocked over.

[TWallace]

They're interesting looking, but I'd avoid them. Mine would hold snails and hermits hostage, as well as steal loose frags and deposit them in bad places, or cause corals to sting each other, sometimes resulting in death to one of them. I finally had enough of my pincushion urchin last night and banished him to the refugium.

I don't know why people consider their coralline-eating habit as a negative. That was the whole reason I got an urchin in the first place.

[Paaxil]

All of the pieces are fairly big (3+ pounds) but they are all resting on each other. Will they wedge in between rocks and push them over? Oh and I really don't care about coralline.

[Paaxil]

Also I have a small two headed frogspawn in the sand, it will probably cause damage to this right? Do their spines poke into fleshy corals?

[prickles]

my advice would be to think more of them as bulldozers. Lotsa power, but not too agile.