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Plan indoor grow room dimensions, plant capacity, lighting, and ventilation CFM requirements for hydroponic cultivation.
Calculate hydroponic reservoir volume from plant count, system type, and refill interval. Size nutrient tanks for DWC, NFT, and drip systems.
Calculate hydroponic NPK nutrient mixing ratios and ppm targets for vegetative and flowering stages. Reservoir dosing guide.
Quality LED manufacturers publish PPFD maps at standard heights. Measure with a PAR meter at canopy level for verification.
PPFD (μmol/m²/s) = Manufacturer spec at heightMultiply average PPFD by photoperiod hours and conversion factor. Lettuce: 12–17 DLI. Tomatoes: 20–30. Cannabis veg: 25–35.
DLI (mol/m²/day) = PPFD × Hours × 0.0036Light intensity drops at edges. Size coverage to the uniform zone, not maximum footprint. Overlapping fixtures improve uniformity.
Effective area ≈ PPFD map 80% peak zoneUpdated: July 2026
Fixture rated 900 PPFD at 18 inches over 4×4 ft — DLI of 29 at 18hr photoperiod, ideal for vegetative cannabis or fruiting tomatoes.
200 PPFD at 16hr photoperiod yields DLI of 11.5 — adequate for butterhead lettuce without tipburn from excess light.
Natural DLI of 8 mol in December plus supplemental LED to reach 15 DLI target for year-round herb production.
Plants need specific light intensity (PPFD) and daily light integral (DLI) for optimal growth. Enter fixture specifications, hanging height, and coverage area to calculate PPFD, recommended photoperiod, and DLI for vegetative or flowering stages.