only time water should smel at all should be when the fish have been transported in the bag for a long time.
+1 on soap in the water, VERY hard to get rid of.
Guppies shouldn't be hard to keep, should be one of the hardiest fish around as long as they don't get stressed (although this reputation has led to a lot of abuse. imported guppies recently have been a waste of time, good bodies, crap tails and a bit of colour, we should be producing a LOT better locally