I never had luck with GBR, and have tried them several times, but they always died within a few weeks to a month. I even tried altering my water parameters... using RO water to soften it, still without success.
About 8 months ago, I heard of a local seller (matt13) on these boards and figured I'd give it another go. Of the 8 I bought 5 are still alive and doing very well.
The chain store Rams come from Florida fish farms, and they are riddled with hormones and disease. I would recommend giving them a try if you can find a local breeder who uses tap water, otherwise contact the seller on this board and I'm sure you will have better results.