temp for goldfish and tetras

Question
My son won a goldfish at the fall carnival, the next day we went to the pet store and purchased a tank and 3 neon tetras. One tetra has already passed away. When I called the pet store back about what the water temp should be the man said "You shouldn't have tetras and goldfish together, they require different water temps." I think they should have said something when we were at the store getting them since we said several times they would be going in with a goldfish, but anyhow, what is the proper temp range for both of these fish? We can't get another tank and I would like to try to make it good for both kinds of fish. Also, I did look at heaters, but none of the ones I saw had any way on them to regulate the temp. Could you recommend some? Our tank is 1.5 gal Tetra brand Whisper aquarium. Thanks for all your help!!!

Answer
Hi Kristi,
Sorry to hear about your trouble and I wish the petstore would have informed you better. All I ever see with petstore advice is always wrong information or they just want tell you what you should hear.

A huge problem here is going to be the small tank size. You just can't really heat a 1.5 gallon safely. And pollution will build up within a day to severe levels in such a small water volume. Goldfish, while small creatures, produce a lot of waste and need space to thrive and be healthy long-term. Something like a 10-gallon would be better. Although not ideal long-term it's loads better than a 1.5 gallon. I say ten-gallons because you can find them anywhere pretty much and they are usually inexpensive. Some even come as "kits" at Wal-mart and include a good filter, heater, and other accessories.

A larger tank is the best solution I can recommend to you. Otherwise, you'll just have re-occurring battles with water quality and temperature issues in such a small tank. :(

I'm sorry for the bad news but I hope this helps!
Karen~