About 3 weeks ago i started a 10 gal. quarentine tank in my kitchen, i threw 4 zebra danios in it, a hang on back penguin filter with bio wheel, a few fake plants and a hand full of gravel from my fully cycled 40 gal. 3 weeks later im showing 0 ammonia/0 nitrites/5 nitrates. During the entire 3 weeks i never once saw ammonia or nitrItes and now it appears i have nitrates.. Could my tank have cycled this fast? ? thanx.