This high CBD strain, a cross between an MK Ultra clone and a G13 Haze male, was originally introduced in 2008 by Resin Seeds in Spain. As they tell the story on their website, this strain helped start the push for high CBD content in cannabis strains. While high CBD content has always been a trait of industrial hemp, Cannatonic was the first strain to selectively breed down THC content, while increasing the CBD content in a cannabis sativa strain. The amount of CBD in Cannatonic is dependent on the chemotype, however, Resin Seeds states growers can expect 75% of the crop, grown from seed, to be CBD-rich. This strain of CBD-rich cannabis is known to test upwards of 23% CBD, and will most frequently contain a 1:1 CBD to THC Ratio.