The black death(For Guppies)
So about three weeks ago I purchased a used twenty-nine gallon tank from a local fish store. The guy added silicon and told me not to add water for two days. So I did was he said and let it cure. Three weeks there seems to be a plague only hitting my guppies. In my tank I have 3 black skirted tetra's, an orange barb, a pleco, and 6 live plants. I originally had 20 guppies, yes I know thats to many fish for an aquarium, but in the past 4 days I have lost 12 guppies. None of my other fish seem to be sick nor dieing so I would like to know if anyone else has had a similar problem or know what could be the cause of their untimely deaths. I would also like to note that I have been taking care of an aquariam for 2 years now and never seen such an epidemic so I don't think its lack of expierence killing off my fish.