dead glo-fish/same day purchase

Question
Just purchased two glo-fish from local store. Acclimated the store bagged fish with my 2 gallon plastic hexagon tank (air tube-no heater)for appropriate time and released fish.  4 hours later they were dead. Unknown chemistry level, temp reading was 80 degrees, tap water w/brand name tap water treatment. Glass stones in bottom.  This is my 4th plastic aquarium in several years. Is this shock? Water temp? Others have told me that plastic tanks aren't good for fish.  Please advise.  Thank you for your response. J

Answer
Hi Joan:  Plastic tanks are fine for fish... it was probably a pH shock issue that killed the fish.  If the tank is fairly new then I am almost positive it was a water chemistry issue like pH... Take a sample of water into the local fish store and let them test it... it is usually a free service... ask them to compare their tank water to your tank water before you buy fish.  The difference should be no more then 1.0 on the pH scale.... dave