I set up a new tank the other day, and used filter media, some gravel, and a bit of water from my old tank. I put 4 zebra danios in, and yesterday ammonia was at .1, nitrIte at .1 and nitrate around 25. Today, I have 0 ammonia, o nitrite, and around 25 nitrate. By my reckoning, that's cycled, am i right?