I have a small hex tank, 2.5 gallons that I am looking to add some fish too. I set it up as a shrimp tank but it keep killing off the shrimp. Its ambient temperature to the house and we keep it hotter during the summer so the tank gets hotter than 80 degrees with the light and top on. Im pretty sure thats what did the shrimp in. Current setup has a single led bulb, a top and no filter but I've gone ahead and bought a clip on light to increase the light and remove the top and I have two mini filters I'm going to try. The tank has an old style Flourite substrate with wood, java moss and Drepanocladus aduncus or Kneiff's Hook-moss. Looking for some tiny, mellow inhabitants that can withstand the range of temperatures from around 65 to 85. No nitrates, no nitrites, ph 7, KH about 60 ppm, GH about 75 ppm. Suggestions?