Introducing Gerbils

Question
Good Afternoon. I recently purchased two female gerbils (now 12 weeks old)for my son and we all totally adore them, so much we have purchased a much larger gerbilarium for them which holds up to six gerbils. We would like to introduce two more females to the gerbilarium. I have read about split cage and cage in a cage technique. Do you think this would work or is introducing two to two a impossible task. ( i do have the time and patience to try the techniques). Your advice is much needed and very welcomed.
Thank you for your time and help.
Claire.

Answer
Dear Claire,
though I prefer the split-cage method better, both techniques will work well. Just make sure all of the gerbils are in the same age range or they'll fight. And you are aware that pet shop owners can make mistakes and read a boy as a girl?
So both techniques, as I said, will work adequately.