[marciemp]

I have read many times here that live fish should NOT be used to cycle a tank. Live rock will cycle the tank it is too hard on the fish to suffer through the cycle. Any fish that do survive will have damage to their gills. If your tank is new the ammonia should spike, then the nitrite usning the live rock alone. You might need more live rock, or you can add a piece of raw shrimp like someone else said, and then don't add any fish until after the cycle, and then add them slowly over time.

Our marine tank is second hand so it was already cycled but I learned the hard way about the nitrogen cycle and how the biological filter becomes established and should be fully established before any fish are added but killing my daughters 2 little goldfish after just putting them in a new tank. I had no idea before but boy have I learned a lot now! I read it takes 3-6 weeks, the best thing to do is test the water, watche the ammonia rise and then fall, then the nitrite will rise and then fall, and after that the tank is cycled. Tests for ammonia dn nitrite should ALWAYS be zero, and nitrate should be as close to zero as possible.