Housing two hamsters together

Question
I recently got two hamsters, Chip and Dale. Chip is a normal winter white and Dale is a sapphire winter white. At first, they got along fine in a small temporary terrarium about 1ftx8in. Then I upgraded to a 1.5x1x1 ft hamster cage with a lookout tower, an external mount wheel and two levels. After they moved into their new home, they started chirping and fighting sporadically. Lately, I noticed that they fight and chirp more often and for a longer period of time. Dale has grown quite large whereas Chip has stayed the same size or got smaller. Also, Dale is much more active. I thought maybe Dale established himself as the dominant male and Chip is being stressed from being chased away from food and water, so he sleeps in the corner all the time and doesn't run around as much as Dale does. I knew this would be a problem upon purchase, unless they were siblings, and Petsmart was sure to give me cagemates but they had no lineage or birth information, and I don't know if the pet handlers just put these two in the same cage randomly and they aren't siblings or cagemates to begin with. Some sources assure that hamsters play fight and is normal, and that they enjoy being in a pair, but I don't think the size and activity difference is normal. Chip is also less comfortable with being handled and nibbles/bites more than Dale. I had to separate them last night, and when I put them back together in the morning, they continued to fight so I put Chip into another container. Chip seems to be more active and less nervous in the few hours that they've been separated, but I'm not sure if I'm just biased because of what I think is happening, or if there really is a problem. I'd like to keep them in the same cage because space and money is an issue (I'm a college student with a dorm room). One website even warned not to interfere with play fighting or they may actually start fighting for real. What should I do?

Answer
Dear Elaina,
thank you for your question.
There is no such thing as play fighting with hamsters, all fights are serious and realy stressful for the animals. They are in constant stress now, even when they are not fighting. Please keep them seperated, they would hurt or even kill each other when housed together again.
Dwarf hamsters are solitary, just as Syrian hamsters. They just tend to live together more or less peacefully for a longer time than Syrians, but eventually the fighting will start.
I hope I was of some help to you
Jennifer