I was wondering if it is normal for having a 75gal. tank for only 2-3 weeks, and all the Ammonia, Nitrite, and Nitrate to be 0 or close. I started it with 40lbs of LS, 20-30lbs. of regular sand for almost a week then added blue damsals and 45lbs of LR, too help the cycle. But have yet to see a...