Hello guys! My 13 gallon tank had 4 guppies inside, 2 platies and I had more recently added 5 neon tetras. Two weeks ago I had to leave for one week, so I changed the water and fed them the day before. One week later I returned to find 2 of my guppies and 1 of my platies dead. The other fish looked fine and the ammonia was zero.The next day after that I had to leave again for another week. When I returned the other platy was dead as well. I changed the water yesterday and checked the paremeters today and everything looks fine! I don’t understand what went wrong. Could it have happened out of hunger? I was told that fish can do fine without food for a week. Do you have any suggestions as to what I can do to prevent this in the future? And what seems even stranger to me is that the guppies and platies who are generally considered hardier than tetras died and the tetras look just fine!