So you got your plant to 8 inches high. Take a nice sharp pair of scissors and wipe the blades with rubbing alcohol to sterilize. On the bottom 3rd of the plant cut off all stems/node/leaves so there is only the main stem bare 1/3 the way up. Change the light schedule to 12/12 and put plant under it, it will stretch, but won't be able to stretch too much due to its need to repair itself. If it does get too high, just gently bend it over by tying string to top and then anchoring to base of plant. Might take a couple of days to bend plant all the way over so you don't snap the thing in half. Be gentle.