Cage question

Question
I recently bought a female rat from Petco; however, I hadn't realized what keeping a rat in a tank can do to the rats immune/respiratory system. I also have been keeping her in a tank. There is a wire cage add-on that I can place on top of the tank in order to give her more room and such. Is this a wise idea? Or should I just save up and buy a big wire cage?

Answer
Unless you can put shelves so she can climb then save up for a cage. Tanks are awful for keeping rats.

You do know that rats need company?

Also buying a rat from petco it will probably have some respitory issues anyway. You should go to a breeder. They dont use unhealthy stock.