cycled tank?

[chumbuckit]

How do you know if your tank is cycled? I have had my tank with only live rock and live sand in it for about 6 months. It built up some green algae on the rocks and glass for the past few months. A week ago I put 10 crabs and a peppermint shrimp in it. They gorged on the green stuff and totally cleared it out over night, AMAZING stuff. I put a brittle starfish in my tank a few days back, he seems to be doing fine.
10 gallon tank, 10 lbs of live rock, couple inches of L.S.

 

[kelly]

After 6 months I would say that it should have cycled. I would check ammonia, nitrates and nitrites, if all are at zero, you should be ok.