Urchin Help..?

[DaviesPats]

hello all...new to this here forum...found it looking for pictures so i figured id join and get some of your points of view...anyhow i have a 40 gal reef tank with 30-35 lbs. LR...a 2 inch crushed coral sandbed...im running an Odyssea 75 Protein Skimmer w/ powerhead and another cheapo powerhead to break the surface tension...also using two 15 reef-sun 50/50 full spectrum lights...anyhow let me cut to the point...i have a clarkii clown, percula clown, arc-eyed hawkfish, chocolate chip star, 3 damsels (2 sergeant majors one blue) and an anenome...i realize that is way too much so no more fish(until the damsels piss me off for the final time and i flush them or they go to my LFS)but im looking into purchasing 2-3 urchins to help keep the algae clean up...i was looking into the pincushins (preferrably the blue tuxedo) but am also looking at the long spined black urchin (problem is he is venomus)...anybody have any suggestions on what to do with the situation or if i should ditch the idea until the damsels are gone...comments welcome good and bad

[leebca]

WELCOME to Reefland

I think you'll find this a comfortable and informative place. Check the sticky posts in the Marine Fish: Care, Health and Disease Treatment Forum.

Urchins:
I'd say you're beyond a reasonable bio-load for that system.

Fishes create (usually) the highest bio-load. Next come the invertebrates. Last on the list are corals. You can have a tank full of corals with no invertebrates and no fishes and have practically no bio-load.

Going by the above, you need to include the starfish and anemone in with the bio-load. The urchins would add to the overload.

Another consideration (especially for the long spined black) is that they will finish off the algae very fast. Your tank isn't large enough nor can it supply enough algae for more than 1/2 of an urchin.

Then, when the urchin is finished with the algae it will begin to eat the coralline algae. They will then eat algae growing on the tank itself. If the tank is acrylic, urchin 'teeth' can and will damage the acrylic. They are also very tenacious. Some urchins will push rocks out of their way to get to food. You don't want to underestimate the tenacity and 'danger' of urchin teeth. If these things are okay and you adjust the bio-load, I think urchins make for very interesting livestock.

Good luck! Hope to see you around.

[John Hamilton]

WELCOME to Reefland


Then, when the urchin is finished with the algae it will begin to eat the coralline algae. They will then eat algae growing on the tank itself.

My tank is virtually algae free and when I put in a small, short spined, pale green urchin, it went straight for the coraline algae. I do have a 175 gallon tank with almost 250 pounds of LR.

[DaviesPats]

i heard scraping off coraline will get it to grow faster...so thats what i did in a lot of areas but i ended up getting i bleieve the same urchin as u(pincushin..green about an inch) and he hasnt dented ANYTHING yet