The last time I wrote about Zac, he was living in a seperate cage to Ira and Gel. About a month ago we decided it was worth trying again to get them to live together. Like last time we started off by getting them out to play together. Then we'd leave them in the same cage during the day while we could keep our eyes on them. We would put Zac back into his own cage at night (actually alternating cages so one night Ira and Gel would be in one cage with Zac in the other, then next night they would be in the other cage).
This time we left it longer before having them in the same cage at night. This seemed to make a difference and everything seemed better with much less fighting and pushing.
Emma wanted to get a larger cage so that they would have more room to run around. She saw the Hamster Castle for sale on ebay decided it would be ideal to keep the three of them in. It is huge (2 foot square), much bigger than the habitrail cages, and required the furniture in the upstairs front room (aka the Hamster Bedroom) to be rearranged.