Since the water bottles are always leaking, maybe try a different brand? This site has a different design of watering bottles for rodents and other small animals. www.agselect.com/ED/showdetl.cfm?&DID=11&Product_ID=996&CATID=30

A good site to figure out if you have enough space for your guinea pigs, is www.guineapigcages.com/ It also shows you how to build your own for about $25

To be honest I haven't seen many pet store brand cages that are a good size for two guinea pigs. There are a few but not many. The above website though has a good minimal floor space for guinea pigs. I kept 2-3 in a 30"x50" cage and it seemed a bit crowded with three. More room the better, as they do get very active and happy when they have room to run around.
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PHLdyPayne