I am a new 10 gal. aquarium owner. I performed tests on my water for a few days before stocking it with fish and found all levels to be normal, aside from hard water and a bit of alkalinity. I purchased 6 fish, one of which was a gouramis. Within 6 hours it had died, not only that, but it's body was lodged in the bottom corner of the tank next to the heater (which seemed strange to me and made it wonder if it had gotten stuck somehow which could have attributed to it's death). It's been a few days and my other fish seem fine. I would like to purchase another gouramis, but would first like to determine the cause of death for my first fish. Is it possible it was just a "dud?" or sick in some way? It didn't really eat anything before it died and strayed away from the other fish (a guppy, 3 tetras, and an algae eater). Any help is much appreciated.