sudden death of neons

Question
I have two community tanks. Until recently I have had no problems.  But all of a sudden three neons died in one day and the next day two more died.  The water conditions are ideal. I have have these neons for approx. five months and the only new additions within the last month were two female swordtails. Help!

Answer
Your swordfish may have been picking on them which would have caused stress which can result in death. Being your water conditions are ideal it makes it difficult to know a cause but I would lean towards the swordfish picking on them. Did you ever see your neons being picked on at all? If you want to keep community fish with semi aggressive fish I would strongly reccommend a well planted tank so they have places to hide. Happy fish keeping.