hi guys..around 5weeks ago, i start cycling my new tank with dead rocks, sand and all the filter media are new. i drop a market prawn in and let the cycle start and im dosing bacteria every 3days. After 3weeks, ammonia-0.25ppm--NO2-0.5ppm--NO3-5ppm. The parameter seems to remain the same after 2 more weeks. Anyone knows whats is wrong?