Cannabis Watering Schedule for Hydroponics

How often do you water cannabis in hydroponics?

In hydroponics, cannabis is fed on a timed schedule instead of an as-needed schedule. Most ebb and flow and drip systems run 1 to 4 short feeds per day during vegetative growth and 4 to 8 feeds per day during flowering. Deep water culture and nutrient film technique run continuously, so the watering schedule becomes a reservoir and top-feed schedule instead.

Cannabis Watering Schedule for Autoflowers: How Often to Water

There is no single number that works for every room. Pot size, growing medium, root mass, light intensity, temperature, and humidity change how fast the root zone dries. A 4-inch rockwool cube in a warm tent can need three feeds a day, while a 5-gallon hydroton pot in the same tent may need one.

how often to water cannabis plants

Watering schedule by hydroponic system

• Deep water culture (DWC): Roots stay in oxygenated nutrient solution 24/7. Top-feed once or twice daily until roots reach the reservoir, then stop.
• Ebb and flow (flood and drain): Flood 1 to 2 times per day in early veg, 2 to 4 in late veg, and 4 to 6 in flower. Flood for 5 to 15 minutes depending on medium.
• Drip or top-feed: 1 to 2 feeds daily in veg and 3 to 6 in flower. Run enough volume to see 10 to 20 percent runoff in drain-to-waste setups.
• Nutrient film technique (NFT): Continuous flow with a thin film over the roots. No dry cycle.
• Aeroponics: Mist 5 to 10 seconds every 3 to 5 minutes. Roots never sit in standing water.

How do you know when to water?

Lift the pot or check the medium by hand before the next scheduled feed. If the medium is still heavy and wet, push the interval back. If it is light and barely damp, shorten the interval or add a feed.

read more

Roots should never dry out completely in hydroponics, but they also should not sit in stagnant, low-oxygen water. That balance matters more than the exact clock time.

How does the growth stage change the schedule?

Vegetative plants under 18/6 lighting drink less than flowering plants under 12/12. Flowering plants can double their daily water use, so expect to add feeds as buds develop. Late flower often needs the same amount or slightly less once the plant stops stretching and finishes.

What about pH and EC in the reservoir?

Keep hydroponic nutrient solution at pH 5.5 to 6.5 so cannabis can absorb nutrients. Check EC or PPM daily in small reservoirs and every 2 to 3 days in larger ones. Rising EC means the plant is drinking water faster than nutrients, so top off with plain water.

Signs your hydroponic watering schedule is off

• Drooping leaves with wet medium: too much water and low oxygen.
• Wilting with dry medium: too little water or a clogged emitter.
• Brown, slimy roots: root rot from warm, stagnant water.
• Rising EC with a stable water level: salt buildup, so flush and reset.

Quick reference watering schedule

1. Veg, small plants: 1 to 2 feeds per day.
2. Veg, large plants: 2 to 4 feeds per day.
3. Flower, weeks 1 to 3: 4 to 6 feeds per day.
4. Flower, weeks 4 to 8: 4 to 8 feeds per day.
5. Final flush week: plain pH-adjusted water on the same schedule.