Today I came home from school only too find a dead neon tetra on my filter guard. Earlier in the week I did notice that a neon had separated himself from the group but woul go back and join after awhile, I didn't think much about it until now. Granted I did purchase my neons from Walmart, but the tank is stable and has been cycled for weeks. I'm going to inspect the retreat to make sure it's not neon tetra disease, and then I'll do a water change and check the parameters just incase. Don't want to lose my school of tetras!