The short answer
A healthy hydroponic photoperiod plant returns about 3 to 6 ounces (85 to 170 grams) of dried flower when vegged for 4 to 6 weeks in a 4 to 6 square foot footprint. Push veg to 8 weeks or longer under strong light and 8 to 16 ounces (225 to 450 grams) per plant is reachable. Autoflowers in hydro land closer to 2 to 4 ounces (56 to 112 grams) per plant. Per area, plan on 40 to 60 grams per square foot, which is 430 to 650 grams per square meter. Yield per plant is a weak number on its own because it changes with veg time, plant count, and canopy size. Yield per square foot per month tells you more about whether the room works.
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What moves the number
- Light: 30 to 40 watts of LED per square foot, with 900 to 1,100 PPFD at the canopy in flower.
- Veg length: each extra week of veg adds canopy, and canopy is what flowers.
- Root zone oxygen: dissolved oxygen above 6 mg/L and water held at 65 to 68 F (18 to 20 C).
- Nutrient strength: steady electrical conductivity instead of swings between starved and burned.
- Genetics: two plants of different cultivars in the same system will not finish the same size.
- Plant count: one large plant and four small plants can fill the same tray and yield similar total weight.
Typical ranges by method
Deep water culture and recirculating deep water culture
Fastest growth of the group. Expect 4 to 8 ounces (113 to 225 grams) per plant at 6 weeks veg, and up to a pound per plant with a long veg and a wide canopy.
cannabis hydroponics autoflower
Drip and top-feed in rockwool or coco
3 to 6 ounces (85 to 170 grams) per plant. Easier to steer than deep water culture and less prone to a single root event wiping out the crop.
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Ebb and flow and nutrient film technique
3 to 5 ounces (85 to 140 grams) per plant in small trays. Nutrient film technique punishes warm water, so it caps out lower in rooms that run hot.
Aeroponics
4 to 8 ounces (113 to 225 grams) per plant when mist cycles and root chamber temperatures stay in range. Recovery from a pump failure is poor.
Steps to reach the high end
- Confirm your state allows home cultivation and stay inside the plant count limit.
- Start from rooted clones of a cultivar with a documented yield record in hydro.
- Size the reservoir at 1 gallon of solution per plant at minimum, 2 gallons is better.
- Set water temperature to 65 to 68 F (18 to 20 C) with a chiller or a cool reservoir in a conditioned space.
- Hold electrical conductivity near 1.2 to 1.6 in veg and 1.8 to 2.4 in flower, then read the plants and adjust.
- Run 18 hours of light in veg and 12 hours in flower, with no light leaks in the dark period.
- Top each plant once above the fourth node, then bend branches outward to level the canopy.
- Defoliate the lower third at day 18 of flower and clear fan leaves blocking bud sites at day 42.
- Veg 6 to 8 weeks for photoperiod plants if you want the largest single-plant weight.
- Harvest when most trichomes are cloudy and about 10 to 20 percent are amber.
- Dry at 60 F (15 C) and 60 percent humidity for 10 to 14 days, then cure before you weigh.
Mistakes that cap yield
- Weighing wet flower and calling it yield. Dry flower is about 20 to 25 percent of wet weight.
- Letting water climb past 72 F (22 C), which drops oxygen and invites root rot.
- Running one reservoir for strains with different finish times.
- Chasing high electrical conductivity because the bottle label says so.
- Harvesting early. The last two weeks add most of the final weight.
How to measure honestly
Dry the whole harvest, trim it, cure it, then weigh. Record grams per plant, grams per square foot, and days from clone to jar. Those three numbers let you compare a 4 plant deep water culture run against a 16 plant drip run and see which one earns its space.