My tank is about 6 weeks old. This is my first tank and I learnt about everything I know after adding the fish. They have mostly survived. The continuing issue I have is that my Ammonia Levels keep rising quickly to 2-4 ppm. Nitrites are always very close to zero and Nitrates are also very low 5 ppm. I panic at the high Ammonia and do a ~75% water change every 2-4 days which brings ammonia down but it is back at 4 ppm within 2-3 days. Have been pouring in Bacteria in a bottle all along. It is a 30 gal tank which according to Aqadvisor is stocked at ~98% with filtration capacity in excess at ~120%. I have not changed the filter pads and have a ton of bio stars in the filter. Readings last night were Ammonia - 2.0 ppm, NO2 - 0, NO3 - 5 ppm, pH - 8.2, Cl - 0, Hardness - 300 ppm, Alkalinity 160. Have been testing with strips as well as API master test kit. No live plants. Plenty of aeration, Water Temp 76-78F, <12 hour lighting, Dont have any dead fish. There maybe a dead ghost shrimp that I am not aware of. Water turned cloudy in the early days but stays crystal clear now. No algae growth. Fish appear to be happy. Do try not to overfeed. I realize that the hardness is quite high but it has also been very low when I use softened eater. That seems to have no effect on the ammonia spikes. What am I doing wrong? Appreciate the help in advance.