Couple of random Questions

[djcanis]

First. I have noticed little green pieces of somthing collecting in areas of my rock. Is this crab poo. It's looks like it could be, but I'm not sure. Do I have to clean it out or is there somthing I can put in the tank to get rid of it.
Second. Will I have to re-cylce my tank if I switch to live sand when I move in a couple of weeks.
And third. My GF is going off to school and wants a small tank for her dorm room. She wanted an urchin, and I'm wondering if it would be ok in a say 5 or 10 gallon tank by itself. A chunk of LR, some CC, a powerhead, filter heater and light. Would this be ok? Any suggestions?
Thanks

 

[birdy]

What type of LS are you getting. If it is truly LS either from the ocean, or established sandbed from a LFS or reefer then you may not get much of a spike, I assume you are going to take all the water and reuse it. And reuse any LR and filters that you have. You may get a small spike, if you do not have an alternative place for your animals you can control the elevated levels with water changes.
As far as an urchin in a nano. I think that is probably not a very good idea, Ophuria would be the best to answer she knows the most about them, but I doubt a nano could produce enough food for an urchin.
The smallest salwater tank I would do would be a 10gallon, but yes, a couple pieces of LR, a sandbed a HOB filter and a heater and light and you can keep a couple small fish and some inverts. I would steer clear of corals though, at least for a while.