Seed listings that promise CBD content up to 20 percent are quoting the best single sample from an ideal grow, not what a typical harvest returns. Realistic home results usually sit several points below the headline figure. What I appreciate on https://calmcbdseeds.com is that strains are listed with a tested range and an average rather than only the peak, which lets you compare fairly across breeders. Any seller showing a single high number and no range is probably doing the same thing everyone does.