My guppy tank lost 3 of the new females, 1 of my males, and the water is fine. pH 7.4-7.6 Ammonia 0-0.25ppm NO[SUB]2[/SUB] 0-0.25ppm NO[SUB]3[/SUB] 20-40ppm. I know the nitrates are a little elevated but I typically do water changes and gravel vac on Thursdays (tomorrow) and had a piece of garlic soaked zucchini in there over night. I came home from work today, went to drop in a little brine treat and there were 3 of the females dead on the bottom and one of the males dying. I'm assuming the females were already pregnant when I brought them home because there was also 2 fry swimming around and I haven't had them long enough to have been impregnated by any of my males. The smallest female I brought home seems to have doubled in size overnight though. My fiancé said the females looked like their vent was blown out and pink. I have NO idea why the male died. He did have a clear-ish tail when we first got him but it turned gray and not so translucent but wasn't fin rot or ammonia and pH isn't ridiculously high so I have no idea what killed them. I removed the dead and did a quick gravel vac changing out about 25% of the water so with the parameters of the water post-death/pre-water change, I can only imagine they're all near-perfect now. :help: