The leaves of the plants WILL turn yellow, there is nothing to worry about. The plant is putting all it's energy into making buds. Continue to fertilize, using the same ratio of fertilizer. Also, here are a few more tips I use. One, juice some mangos and add that (about one ounce per plant to the fertilizer liquid or just water) to your plants twice a week. Mangos contain TERPENES, like any fruit. Terpenes are what give marijuana their distinctive smell and flavor, increasing the smell and flavor of the plant, and might increase potency also! I don't recommend you use pre-made mango juice. It contains only 20 percent mango juice and a lot of sugar. Also, go out and buy BLACK STRAP MOLASSES. Mix one teaspoon per quart into the fertilizer or water mix. BSM has a certain type of sugar that pot plants use readily. This will help to increase bud thickness. Also, if you want, i would recommend using TONIC WATER, which has CARBON DIOXIDE, which the plants use immediately once it is poured into the soil. DO NOT use club soda, it contains quinine, which could kill the plants!! I recommend FLAVORED tonic water, such as Adirondack tonic water, which has flavors such as WHITE CHOCOLATE (MY FAVORITE), and one that smells like bubble gum (wild berry), which I am using on my blueberry and super silver haze plants, along with the white chocolate. The carbon dioxide gives the plant a boost, and in conjunction with the mango juice, black strap molasses and tonic water, is a potent blast that will help the plants make nice, big, thick buds. Now, as far as the yellow leaves are concerned, you should use a method called DEFOLIATION. That is when you pull off ALL of the fan leaves (the large ones), leaving only the top fan leaves. This forces the plant to put it's energy into making side shoots, where the buds come from. You can do that after about one month, when the plant is mature enough to handle it. You can smoke the leaves and get a good buzz. Just dry them in the microwave. Here's how. Take two pieces of paper towel and wet them so they are fairly wet. Place the leaves between the two pieces of wet towel, folding over the sides and front so the steam stays in the towels. Set the microwave at 30 percent heat, and set the timer for about 3 1/2 minutes. Start the microwave and check the pot after about 2 1/2 to 3 minutes so it doesn't overdry. After 3 1/2 minutes, take it out and check it. It should be almost dry and kind of sticky to the touch. If it isn't dry, then put it back in the microwave at 30 percent power again for 30 seconds, checking it every 15 seconds. You may have to add MORE time or less, depending on your microwave and how powerful it is. It is a matter of trail and error because each microwave is different. NOW ENJOY! If you do this correctly (the defoliation), you can have smoke ALMOST EVERY DAY until you pull them for the harvest! I would also recommend you use LIGHT STRESS TRAINING, which is taking each branch, bending it down, and using twist ties, tie each branch LOOSELY as not to damage them, and pull them down to expose the center, tying the twist tie to the pot by creating a hole, or by taping it to the pot. This allows the center to be exposed, allowing more light and air to get through, increasing the amount of side branches, which means, more buds. It may look funny having a naked plant along the sides, but it pays great dividends in the end with more buds. I recommend CFL lights because they don't produce a lot of heat, and you can keep them INCHES from the top of the plant without damaging the plant, making the plant BUSHY instead of stalking when using hot lighting. Hope that helps.
