Tank has been cycling for 5 1/2 wweeks now. Nitrite is still at 0.05, but Nitrate has risin very high to 20 and ammonia has risin from 0 to 0.25 again, why does this keep happening? Lights are almost always off. Skimmer is running for 4 days now, and doing GREAT! i just cleaned rinsed it out. I threw in a a raw piece of shrimp at week 2.