Start a home cannabis hydroponic grow with a small deep water culture (DWC) system: one 5 gallon reservoir, 2 to 4 net pots, an air pump with airstones, a 3x3 foot grow tent, a full spectrum LED, and a two part nutrient line. Fill the reservoir with water, add nutrients at about one quarter of the label strength, set pH between 5.5 and 6.3, and run the light 18 hours on and 6 hours off. Expect 10 to 14 days in seedling stage, 3 to 5 weeks of vegetative growth, then 8 to 10 weeks of flower.
Prerequisites
- A state and local law that permits home cultivation, plus the plant count limit for your address.
- A space with a door or zipper that blocks light, holds humidity, and has room for a tent.
- A water report or a test strip reading so you know your starting pH and hardness.
- Budget for gear, nutrients, and electricity for one full cycle.
Steps
- Confirm your state allows home growing and note the maximum plant count. Rules are set at the state level, so check before you buy seeds or gear.
- Choose the system. DWC uses one reservoir and one airstone per plant and has the fewest moving parts. Ebb and flow and drip systems work too but add a pump, timer, and flood tray.
- Pick the grow space. A 3x3 foot tent holds 2 to 4 plants and fits a closet or spare room. Keep it away from bedrooms you sleep in if odor matters.
- Buy the core gear: reservoir with lid, net pots, clay pebbles, air pump, airstones, tubing, pH meter, EC or PPM meter, thermometer, humidity gauge, timer, and an inline fan with a carbon filter.
- Start seeds in rockwool cubes or root clones in a propagator. Keep the cube damp, not soaked, and hold the dome at 75 to 80 F.
- Move each rooted seedling into a net pot filled with rinsed clay pebbles. Set the water level so the bottom inch of the pot sits in the solution.
- Mix the reservoir. Fill with water, add nutrients at one quarter strength, stir, then measure. Adjust pH to 5.5 to 6.3 with pH up or down.
- Run the air pump 24 hours a day. Dissolved oxygen keeps roots white and stops the pathogens that cause rot.
- Set the light cycle. Use 18 hours on and 6 off for vegetative growth. Switch to 12 hours on and 12 off to trigger flowering.
- Check pH and EC once a day. Top off with plain water as the level drops, then recheck pH after the top off.
- Drain and refill the reservoir every 7 to 10 days with fresh nutrient solution. This clears salt buildup and resets the nutrient ratio.
- Hold the environment at 70 to 80 F with 50 to 70 percent relative humidity in veg, then drop to 40 to 50 percent in flower.
- Flip to 12/12 when the canopy fills about half the tent height. Plants stretch for the first two weeks of flower, so leave headroom for the light.
- Harvest when most trichomes turn cloudy. Dry trimmed buds at 60 F and 60 percent humidity for 7 to 10 days, then cure in jars for 2 to 4 weeks.
Problems to Watch
- Brown, slimy roots: root rot from warm water or low oxygen. Chill the reservoir below 70 F, add oxygen, and rinse the roots.
- Green film in the reservoir: light reaching the water. Seal the lid and block gaps in the tent.
- Leaf tip burn: nutrient strength too high. Drop EC by 25 percent and refill.
- Yellow lower leaves: pH drift locking out nutrients. Reset pH and refill the reservoir.
Timeline and Cost
A first DWC run takes 14 to 18 weeks from seed to jar. A 3x3 tent setup with light, fan, pump, meters, and nutrients runs roughly 400 to 700 US dollars, and a single cycle uses about 200 to 350 kilowatt hours of power depending on light wattage and schedule.
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