If I were you I would take 3 or 4 clones from the Hashberry before you put it into flower. The clones make better plants than the ones from seed. I think if you drop the ph of your water down to 6.3 you will have better results. The grow I'm doing now is all Mandala from clones... Kalichukra, Satori, and Mandala #1. They were all veg'ed for 8 weeks the Kalichukra and Mandala #1 were 32 inches tall topped going into flower. The Satori was 26 inches going into flower. After 4 weeks of flowering the Mandala #1 plants are about 50 inches or more tall with multiple colas. The Kalichukra is about 60 inches tall with multiple colas and the Satori is around 50 inches with just single colas. Damn nice looking plants all.
They were fed Fox Farms Nutes from the beginning every other watering. The other watering was (is) just plain ph'd water. The attached picture is a Satori plant that was harvested last month. It was 30 inches tall at the finish and produced over 2 oz of dried bud.