Teddy bear hamster/fighting/housing.

Question
I bought 2 long-haired teddy bear hamsters for my kids about 1 month ago. Their names are Elephant and Flower and they are both female. They are approx 2 months old and they are sisters. They started out about the same size but I have noticed that Elephant is starting to fight with Flower and am noticing that Elephant is gaining weight faster than Flower. When I bought the hamsters the pet store informed me that they would do better if there was 2 of them for companionship but every evening they will get into several fights and Elephant will chase Flower around the aquarium pinning her in a corner usually Flower ends up upside down and then Elephant backs off. I've noticed that Flower is missing a toenail and her nose is a little scratched up. Do you think this behavior will let up? I don't want anythng to happen to either one of them.

I was also wondering if I can get some ideas on what to purchase for the aquarium as far as entertainment. All I have right now is a water bottle, igloo and wheel.  I have a metal top for the lid but I have to put heavy things on top of it because they will get on top of their wheel and try to push it open (I don't know if they can or not). They will also try to climb the water bottle. So far, no escapes but I really don't want there to be a first. :)

Also wondering what is the best kind of bedding and food.
I have tried researching all of this but every where I go there seems to be a different answer. I just want to make my pets comfortable and I'm new at the little pet thing.

I appreciate you taking the time to answer my questions.
Thanks, Sarah

Answer
Please do independent research before ever bringing an animal into your home. Syrian hamsters are NOT supposed to live together regardless of what the pet store tells you, they simply don't know or don't care. They grow into adulthood and fight each other over cage territory. One becomes dominant and pushes the other one around, which is what's happening to yours. You need to buy a separate tank immediately. I'd go back to the pet store that sold them and make a fuss about the ignorant sales people, one of the hamsters could have died through this territory fighting.

Depending on how big the aquarium is, tubing is the best toy. If your using a water bottle holder that's big and bulky, remove it. Use a bell bottle style water bottle with a loop at the top, and secure it to the tank with a bent paper clip. It will stop the climbing since they'll have nothing to grab on to. I had a hamster that escaped climbing the water bottle holder and chewing her way out while I was on vacation.

Use nothing but Aspen wood or recycled paper bedding, it's your choice, just no other wood bedding. Any food that has a variety of ingredients like KayTee Fiesta is what I recommend. Dried fruits and veggies, dental crunches, seeds, pellets, the works.