So a decade or so ago, guppies were my introduction to fish-keeping. I got frustrated by the repetitive unexplained deaths from the pet store ones and, being the good little Bio major I was, spent the next four or five years breeding my own much hardier snakeskins and halfblack pastels. Then I moved, had to abandon the hobby for a while, and am only now revisiting guppies because my spouse adores the pretty colors. My hope was that generally available guppies would be at least a *little* better than the ones I started with 11 years ago. 5-gallon tank, dirted, cycled, planted, 76F/7.2/0/0/10 (/3kH/8gH), 4 healthy looking male fancy guppies from large local store. Twice weekly 40% WC. Careful observation to make sure nothing more than displaying is going on. Ten days later, I just returned three dead guppies. Argh! I don't want to do the whole linebreeding thing again! I have other fish to focus on! Why must these fish be so darn fragile?!