when i first started my first tank i got several neon tetras and a couple of young guppys from the petshop the neon tetras died over noight along with the guppys, a few weeks later i brought more neon tetras to keep the neon tetra who didnt die company all of them died again overnight ph and amonia levels were normal so i was left with 2 remaining neon tetras a week later they died, both of them to. recently a friend of mine started a tank i gave them some of my guppy fry that were a month old (i got their parents from a breeder), and themn she brought some neon tetras all of a sudden the tank water and the guppies became sick same with the neon tetras i fixed the problem butmost of the neon teras died and the guppys any ideas on what the problem is? they were perfectly fine in the petshop :bounce: