Marco Rock Cycles

[Blom]

Tanks been running for about a week now and with today's H2O test I found that my tank had cycled. Ammonia, Nitrites and Nitrates were all zero. Last time I measured these values I saw a spike in Ammonia, but that was only a few days ago. I know there isn't a lot on the rock to die off, but there would surely be some. Just curious on what others had found.