I'm into about a week of a raw shrimp cycle. I also put in a filter cartridge from a buddy's tank, but he left it out for several hours, so I'm not sure if any bacteria survived. Anyway, for about the past 5 days, I'm getting the same readings. Ammonia 4ppm, Nitrites 1ppm, nitrates .5 ppm. After 5 days, shouldn't the nitrites be getting higher? Is this normal.