Here's a little blip I found on a government website. Note that it says THC levels of indoor marijuana from the U.S. and Canada are typically under 15%. It's all the same stuff.
"Marijuana potency has increased; however, even with the advances in indoor cultivation techniques and marijuana production methods used throughout the United States and Canada (where much of the higher potency marijuana is produced), THC levels remain, typically, under 15 percent. Growers can and do produce marijuana with potency levels over 20 percent; however, not all growers have the capability or the determination either to produce top quality marijuana or to achieve the highest potential yield from their crops. Increasingly, organized crime groups in Canada and, to a lesser extent, the United States are becoming more involved in large-scale marijuana cultivation and are primarily interested in profits. It is unlikely that they will invest the care required to mass-produce top quality marijuana, particularly in the drying, manicuring, and curing stages of production. This trend should help to stabilize or further slow the rise in average potency levels."
http://www.usdoj.gov/ndic/pubs11/13846/marijuana.htm
From the same site: "The escalating prevalence of higher potency marijuana such as sinsemilla has resulted in an increase in average marijuana potency; however, high potency marijuana constitutes a relatively small portion of the marijuana available throughout the United States. Commercial-grade marijuana is the most widely available type throughout the country."
From the same site: "The escalating prevalence of higher potency marijuana such as sinsemilla has resulted in an increase in average marijuana potency; however, high potency marijuana constitutes a relatively small portion of the marijuana available throughout the United States. Commercial-grade marijuana is the most widely available type throughout the country." Sinsemilla is not a strain of marijuana but rather an unpollinated female plant with bigger flowers/buds because the plant doesn't divert any of its energy towards seed production, it just grows bigger buds and hence produces a higher yield or crop. Potency is determined at a genetic level, some modern hybrid strains from Holland are more potent than others, but don't let the Government confuse you because they do not know the difference between potency and yield.