Buying new fish for your aquarium...

Buying New Fish For Your New or Existing Aquarium

You should always purchase your fish from a reputable place. Check that the dealer adopts proper quarantine procedures before he places the fish for sale in his/her establishment.
Look over the tank that the fish is in that you are considering for purchase. Do not buy a fish from a tank that has sick tankmates.
If a fish is lying listless on the tank's bottom you may consider the fact that the fish is unhealthy. Unwell fish will "hang back" or be slow to react when someone gently taps the glass.
Do not buy a fish that has visible signs of illness or disease.
Do not choose a fish that has dead tankmates in with it. (you don't know the reason for the deaths)
Check the fish guarantee.

Remember before adding fish to a newly set-up tank, that death can result if the tank has not completely cycled.