I know I've posted multiple threads in the past about this, but I still haven't figured it out. Today I had another fish die with no warning. The only signs I've sometimes noticed is lack of appetite and loss of color. This time, just found a hatchetfish stuck to the filter. Keep in mind I started with 7 of these in qt for 3 weeks. After this death I'm down to only 1. At the same time I bought the hatchefish I also bought 6 cardinal tetras and 7 African dwarf frogs. Over the course of 2 weeks, all the cardinal tetras died and all of the African dwarf frogs lived (both were in a cycled and planted 20 gallon long). African dwarf frogs were well fed and didn't show signs of aggression. Within the past few days I've noticed another rummynose tetra losing color, appetite, and size. Let me rephrase a lack of appetite to rather just that they can't swallow the food. What the heck do I do? I tested my pH and found it was about 8.2. Nitrates around 5, ammonia and nitrite at zero. I work an internship with a local university for chemistry research so maybe I could ask them to inspect my dead fish for diseases. Other than that I'm completely lost and I really want to give up and just do something like a flowerhorn lol.