So I have been having some difficulties with my new 15 gallon tank. I set it up on 4/26/15. I did a 10 gallon to 15 gallon switch over. I used my old rocks, old plants, as well as water. I just added an additional 5 gallons of water and a new decoration or two. I also let my old filter run in the new tank while the water was heating up to temp. At the time of set up I had 7 fish and 2 shrimp. I thought it would be fine to transfer them right in since I was using most of the old stuff. After a day or two after the set up everything started dieing except for one ember tetra that now has died about 2 weeks ago. I've been testing my water periodically throughout the couple months the tank has been set up. My ph has been high at 8.2 (it was the same in the old tank, could never get it down), my ammonia at one point was 0.25,last time I checked it looked to me like 0, the nitrite is 0, and the nitrate is 5. Since I had decent last readings I decided to add a new fish to see how things went. I added a balloon molly who sadly only lasted a few days. I am not sure what my problem is with this tank. I would love any input so I can figure out my problem and have a happy healthy tank. Thanks!