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This will start out with you watering the plants every couple of days when they're small, and may end up with you watering them once a day towards the end of the plant's flowering cycle. Ensure that at least a little extra run-off water comes out the bottom of the container whenever you water your plants to ensure that unused nutrients don't build up in your medium. Coco coir and perlite are very forgiving if you accidentally over or under-water your plant, but make sure to adjust your watering schedule accordingly if you notice your plant's leaves are wilting or drooping. You can keep your marijuana plants in the vegetative stage by giving them 18-24 hours of light a day.  Your marijuana has two major grow phases after it's a seedling, the vegetative and flowering stages. You will treat the plant differently depending on what stage it's in. During the vegetative stage, your marijuana plants are only worried about growing and getting big. In order to keep your plants in the vegetative stage, they will need to get at least 18 hours of light a day. This simulates "summer," when the days are long. You can give your plants as much as 24 hours of light per day during the vegetative stage, but you'll find success as long as you stay within that 18-24 hours or light per day range. The height of the plant is often the main factor when determining how long to keep your marijuana plants in the vegetative stage. Your plant can double its height in the flowering stage, so you will want to keep the plant in the vegetative stage until it's about half it's desired final height. If growing in a closet, it's a good idea to keep your plants in the vegetative stage until they're 6-18" tall. Tell your cannabis plants to begin the flowering stage by changing to a 12 hours of light/12 hours of darkness schedule so that they start producing buds. This simulates the beginning of fall and winter. In the flowering stage, your plants stop worrying about growing as much, and start putting their energy into growing flowers/buds. You will need to tell your plants when it's time to start flowering. In the wild, marijuana plants start flowering when the days start getting shorter because that's a sign that winter is coming. In order to simulate the same conditions, you will need to switch your light schedule so that your lights are on for 12 hours a day, and off for 12 hours a day. Determine the gender of your plants 1 to 2 weeks after first changing the lights for the flowering stage. Get rid of any males you happen to find in the bunch. Males will pollinate females, causing females to start diverting energy from THC production into seed growth. Pollinated weed isn't unsmokable, but it's a lot less potent than unpollinated weed and picking out seeds can be a pain. After making the switch in light schedule, you will start noticing the first signs of your plant's gender about 1-2 weeks. Female plants will grow white hairs and males will start growing grape-like balls that eventually become pollen sacs. In order to maximize on the amount of bud you get, you will want to make sure you remove any male plants so they don't pollinate your females. If male and female plants stay together, than your females will end up making lots of seeds instead of buds. You also don't get any usable bud off of a male plant, only pollen. This is often the toughest part for beginning growers. The Flowering Stage can last from 6 weeks to 12 weeks or longer depending on the marijuana strain that you're growing with. Otherwise, you may actually be able to taste the nutrients in your final buds (your marijuana could have a chemical after-taste). This process is typically known as a flush. Towards the end of your plant's flowering cycle, you may notice that some of the oldest leaves start turning yellow and falling off. This is totally normal and is a sign that your plant is taking nitrogen out of the leaves and putting them into the buds/flowers. This is a signal that it's getting close to harvest time, and you'll usually want to stop giving your plants nutrients with their water for the last 1-2 weeks to ensure the best possible taste of your final bud.
Water your plants with pH'ed and nutrient-filled water whenever the top of the coco coir starts feeling dry. Keep your marijuana plants in the vegetative stage of growth until they are about half their final desired height. Start the flowering stage when your plants achieved the correct height. Sex your plants and get rid of any males. Wait patiently while your plants mature in the flowering stage. Start feeding your marijuana plants just plain, pH'ed water 1-2 weeks before it's time to harvest.