Ok..... what would prob work pretty good is.....
ask your local fish shop when the new fish come in
be there on that day
get 3 very fat female guppys straight from the shipping bag if possible
take them home to a tank with a nice fresh bunch of weed
raise up the horde
guppys do best when raised up from fry in your particular death water
other than that you should prob look at your basics
filter first as it needs to be working biologically and not blasting the
guppys to pieces
Food is next, don't be cheap!!! some spirulina flake or frozen brineshrimp
will get you well on your way to success
water... as mentioned salt and I recon a handful of shell grit never hurts
livebearers..
guppys have hundreds of diseases but with good water and food they are still
tough *******s!
:-)
don't keep the tank too clean
wash the filters in water from the fishtank NEVER in tapwater
try only do 25-30% water changes....
works for me anyway
good luck