that's very bad advice ... do NOT cut your tops like a hedge ... you will stress your plant, and likely wind up with a hermaphroditic plant, male flowers ... search this website for 'LST' techniques (low-stress training) ... simply put, you just bend the plants over, and tie them down ... also, remember, you do NOT have a 'huge' plant at 3' tall, this is a plant that may grow 10'-15' tall outdoors, you are doing quite well to hold it to 3' ... you also need to maintain 18" or more distance from your high-pressure lamps, or your plant will suffer light-bleaching (this happened to me once, as I ignored the '18"-30" rule-of-thumb' and kept getting closer and closer) ... also, don't pick your bottom yellowing leaves off, either ... the plant is drawing nutrients from them until they drop, and also can stress the plant ... when in doubt, imitate nature's way (nature doesn't clip plant tops, etc) ... good luck ! :jointsmile: