you're probably going to have a hard time finding a low thc strain. in my research, the lowest ive seen (according to the websites anyway and who knows how accurate it is) was 16.8%..or 18.6%, i forget. you're best bet would be just gettin some mediocre bag seed and grow that or find a strain that is used to treat high anxiety/panic attacks. just my two cents.
Naw you shouldn't have a hard time at all finding strains with a stated THC content of under 12%. As far as the 16.8 or 18.6 percent goes, those kind of numbers are really really optimistic, and are only attained by master growers maintaining pefect conditions. Keep in mind that the numbers you see on seedbank websites for THC content are usually highly inflated and almost always higher than most RIU growers will ever acheive. Almost NO weed you'd buy at a Collective of from a corner dealer is going to be anywhere NEAR that. Most casual growers have never ever and will never grow weed with that kind of THC content.
Dig This: In a nearly 40 year long ongoing study, the University of Mississippi's Drug Monitoring Program has taken up the task of determining the average THC content of the U.S.'s supply of commercially available marijuana. They found that the average levels were MUCH lower than people expected. In 1973 the average levels were as low as 0.83% on the bottom end and only 2.5% on the high end. In 2004, the statistics varied from 5.81% to 8.1%. I know, I know - ill probably hear it from every single grower on here who grows bomb ass spaceweed with 30% THC and shit, but the fact is that weed with even 12% THC is fucking bomb.
You CAN harvest a couple weeks early if you want to lol just seems like a massive waste of time to me. You're gonna gain a lot of weight in the last two weeks, not to mention flavor. Like running a marathon and then turning around and going home as soon as you see the finish line...