Dead Goldfish. Can You Help?

They are supposed to be compatible, and don't fight. Maybe the gold fish have a fungus that is killing them off. Hope this helps.

Gold fish usually don't last very long, at least that is what I have heard.  If your guppies make it then maybe there was something wrong with the goldfish.  Some times depending on when you bought the goldfish you can take them back and replace them if they die before so long.  There could be something wrong with the water, you may need to add something to it to clean it.  I would ask the pet store for sure though.  Maybe wait to see how your guppies do first.  You could also have under fed them or over fed them.  But I have not had much luck with cheap gold fish.  One store told me when you buy them, when you leave the store hold the fish above your head.  Because most of the stores have those revolving sliding doors and there is some kind of laser light that goes through and if it hits the fish it can make them sick and kill them.  That is also why if you have a radar detector in your car, it will go off when you pass  certain stores that have those kind of doors.  I am not sure if that is true, but that is what I have been told.  I still cant keep fish alive.  No matter what I do and buy, and the tank.  This is just some things I have heard.  Good luck.