Prismarine Shards are items added in 14w25a that can be obtained by defeating the Guardian mob. They can be crafted into Prismarine variants such as Prismarine Brick and Dark Prismarine.
After veg they will usually flower for anywhere for 8 to 9 weeks. The breeder recommends growing Jack Berry F2 in a SCRoG type grow, where the yield can reach above average, at best. This is a strain that spends most of its energy developing trichomes, rather than bud mass. Don't expect huge yields with this one. In most cases, it simply isn't possible.
The F2 is bred to a bengal and the kittens produced are called F3's. The F3 is bred to a bengal and the kittens are NOW CONSIDERED SBT (stud book tradition meaning at least 4 generations away from the leopard cat) BENGALS or F4's. Most breeders do not label their kittens on their site as F5, F6, F7 ......