Hi All - It has been a while since, I logged on. I now have a problem and I figured you guys were the experts....I have a 50 gal tank, that has been set up for 4-5 years. All was well, but I got a sick fish, and my mom I think od on the medications, trying to save the fish...Fish eventually died, but the tanks has not been right since...Water got cloudy, would not clear. I thought maybe beneficial bacteria had been distroyed and tank needed to go through a cycle again. This has been going on for a couple of months. I have mollies in that tank...So i know the tank is over loaded...We have about 20 adults and 100 babies...lol...My mom loves the little ones. The tank was heavily decorated, and I removed a lot of the decorations, and did find some dead fish. I also changed the filter as usual before I realized there was big problem. Fish were stressed because the numbers were off the charts...I tested this am and they are as follows...Nitrites 4.0; nitrates 160; ammonia 0; ph 7.4...I have been doing small water changes to keep fish happy...Any recommendations would be greatly appreciated. I also found out Mom had added Amequel to tank, because she went to Petsmart, and that is what they told her to do..Pleas help...thanks Jan