Hello. I set up my first 55 gallon tank a month ago. My goal is to have a community tank I currently have 4 dwarf gouramis, 6 neon tetras, 3 loaches, and a pleco. Every thing was going fine, until 4 days ago. Tank had been getting bi weekly 30%-50% water changes. I have a hang on back marineland penguin 350 bio wheel filter,and a under gravel filter,with 2 power heads. I noticed a strong fishy smell coming from the tank 4 days ago, so I did a water change and replaced filter media because it was a month old. I use a gravel vac to clean the gravel, when I do my water changes. I don't think my biological filter has been established yet, because I'm still getting ammonia and nitrite fluctuations, 0 ppm,and as high as .5 ppm, on ammonia and 0-5 ppm on nitrite. nitrate is almost always 0 ppm ph is always steady at 7.8. so now that my tank history is done, my problem is after my last water change/filter change 4 days ago, my water got really cloudy, and you can see a lot of particles floating in the water. so I did a 75% water change today, and water clarity has not improved. What am I doing wrong?