How much do Urchins eat?

Im thinking of getting an urchin for my tank. i have alot of algea on the glass. my emerald crabs take care of my rocks. What is the best urchin for a reef tank and how often do they run out of food?

 

Their mouth is on the bottom. They scrape algae off of everything.

Here's a pic of the underneath of mine when he was on the glass.

 

Urchins have been known to completely wipe out a kelp forest off the Pacific northwest coast.

 

so what would be the safest one to get for a reef tank? i was thinking of the blue tuxedo

 

tuxedos are pretty cool, but they may pick up pieces of your reef and carry it with them...including your crabs. I like the short spine myself, as he's proven himself a very effective algae eater on all surfaces except the sand.

 

ok thanks. i havnt seen any short spine urchins online. they are always either long spine or pincushin. Looks good though. im going to my LFS this week to see about ordering one.

 

Let me see if I can get you the latin name, so you know just what to ask for...ah, here it is:

Strongylocentrotus purpuratus

 

that will come in really handy. Thanks everyone

 

An urchin will probably eat all your alage and then starve. You may feed him algae sheets.

 

Most urchins, except the Pencil urchin, will be reef safe, all of them eat the same basic thing, and they never really "eat until full then rest". Both of mine constantly stay moving and grazing on whatever they find that has algae, leaves a nice white rock streak behind them.

 

i have nori sheets i could use to supplement when the algea runs out

 

i think im going with the short spine. im going to order one today and the LFS said it would probably be in next week sometime. i will probalby add it with a blue linkia star. my bottom is getting pretty over grown and my sand sifting snails are not really doing enough. do those urchins add much to the bioload?

 

I have had mine for years.......he even has algae growing on his spines and the hermits hitch a ride and clean him off. The seahorse used to anhcor himself to him and get a free ride also

 

He is basically a free creature, part of the CuC ive never had to supplement my shortspine with sheets, its been over a year, so take it as you will.

 

ok. i went and picked an urchin up yesterday. I was going to order one but they where on sale in the store for $10. i thought that was a good price