Guppies can live in a wide variety of water temperatures and water conditions. This does not mean you can put your fish in an abusive environment and they will thrive though. However, they can live through short periods of unclean water.

Guppies can live happily in temperatures from 60 to 90 degrees F (15-30 degrees C) but are happiest in the mid 70s (low to mid 20s C). Although they are fresh water fish they do well with a little bit of salt, about 1 tablespoon for every 5 gallons of water. The pH of the water is best between 7.0 and 8.5.

Since guppies are smaller fish they really like live plants in their aquariums. The live plants will provide shelter for their babies and a home for any live food which will feed them (microscopic organisms).

A gallon or two of water is recommend for each fish, so a 10 gallon tank should not hold more then 10 adult guppies. With filtration and water changes you can have more.

Water changes are needed for guppies, like with all fish. Changing the water will remove chemicals which your filter or plants can not get rid of which will end up poisoning your fish. Since guppies are small they produce less waste then larger fish, but a 10% water change per week is recommended to keep your fish healthy.