I'm looking forward to popping some "Blackwater" seeds from Cali Connection. GDP is a great strain but the yields are real low. Although, for not getting heavy yields you do get some really dense nugs which can lead to bud rot in a really short period of time even if you're running a dehumidifier because the nugs are so dense. Also, been my experience that soil conditions and also if it's not that cold at night the plant won't really turn purple. GDP is also a really leafy strain. It takes a lot of thinning of the canopy to make sure the lower buds have any chance of getting light and air. Can't buy seeds of GDP but what I would suggest if you're looking for a really good purple/black strain is OG Kush crossed with Mendocino purple aka "BLACKWATER". A real black purple OG. The OG should add a real kick and also help the yields a little bit.