Cannabis Watering and Feeding Schedule by Stage
By The Budometry TeamPublished Updated
Use this as a starting framework, then adjust based on how your specific plants respond. Genetics vary more than any chart can capture.
Part of our pillar guide: Watering and Feeding Cannabis: Water Types, EC and Schedules
Stage targets
Values are total dissolved solids on the 500 scale, including what is already in your water.
- Germination: plain pH'd water, 6.0-6.5, no nutrients
- Seedling: 150-300 ppm, quarter strength, Cal-Mag if on RO
- Early veg: 400-700 ppm, nitrogen-heavy base
- Late veg: 700-1000 ppm, plus silica for stem strength
- Early flower: 900-1200 ppm, shift toward P and K
- Late flower: 1000-1400 ppm, K-heavy, then taper
- Final week: plain water or heavily reduced feed
Additives worth using
Cal-Mag for RO and coco growers, silica for stem strength and stress tolerance in veg, and mycorrhizae at transplant to speed root colonization. Most other bottles in a store are optional.
Adjust to the plant
Slight tip burn means back off by 100-200 ppm. Pale, slowly-yellowing lower leaves in mid-veg means feed more. The chart is a hypothesis; the plant is the data.
Frequently asked questions
- Should autoflowers use these numbers?
- Run autos at roughly 70-80% of these values. They are smaller and burn easily.
The full guide on this topic
Watering and Feeding Cannabis: Water Types, EC and Schedules
Which water to use — RO, city, well, softened or distilled — plus EC and ppm targets by stage, Cal-Mag rules, runoff percentage, and how to fix nutrient burn.