Coco Academy v1.0 Beta

Light Management & Calculation

Optimize your lighting setup and plan your grow cycle effectively.

Light Hanging Height Estimator

Estimate optimal light hanging height based on your light's wattage, grow area, and target light intensity (PPFD).

Enter the actual power draw of your light.

Area of your grow space (e.g., 4 for 2x2 ft).

Desired light intensity. Typical: Seedling: 200-400, Veg: 400-600, Flower: 600-1000+.

Important Light Considerations

This calculator provides an *approximation*. Actual optimal hanging height depends on your specific light. Always observe your plants. A PAR meter provides the most accurate readings.

Electricity Bill Impact

Estimate the electricity cost of running your grow lights.

Grow Cycle Light Schedule Estimator

Plan your plant's light cycle transitions from seedling to harvest.

Understanding Light & Plant Response

Purpose of Light Changes (Photoperiodism):

Cannabis is a photoperiod-dependent plant, meaning its life cycle stages are triggered by changes in light duration. This is called photoperiodism.

  • Vegetative Growth (18-24 hours light): Long light periods signal the plant to focus on developing leaves and stems, building a strong structure.
  • Flowering (12 hours light, 12 hours darkness): A reduction to 12 hours of uninterrupted darkness signals the plant to switch from vegetative growth to producing flowers (buds).

Autoflowers are Different

Autoflowering strains do not rely on light cycles to flower; they transition automatically based on age. However, consistent light is still beneficial for their growth.

How to Carefully Change Light Cycles:

Transitions should be smooth to minimize stress:

  • Consistency is Key: Ensure the dark period is truly uninterrupted. Even small light leaks can confuse the plant and cause stress or re-veg.
  • Gradual Reduction (Optional but Recommended): Some growers prefer to gradually reduce light hours (e.g., from 18/6 to 16/8, then 14/10, then 12/12 over a few days) to ease the transition into flower, though a direct flip usually works fine.
  • Monitor Plant Response: After flipping to 12/12, observe for stretching and the appearance of pre-flowers within 1-2 weeks.

What Over-Lighting Looks Like (Light Stress):

Too much light, even without direct burn, can stress plants, leading to reduced growth and nutrient uptake issues.

  • Tacoing/Cupping: Leaves curl upwards at the edges, resembling a taco.
  • Yellowing/Bleaching: Top leaves directly under the light may start to yellow or look pale, even if other nutrients are sufficient.
  • Stunted Growth: Plants may stop growing vertically, and overall vigor decreases.
  • Nutrient Deficiencies: Can induce calcium or magnesium deficiencies due to increased transpiration and nutrient demand.

What Light Burn Looks Like:

Direct damage from lights being too close or too intense.

  • Crispy/Burnt Tips: Leaf tips and edges closest to the light turn brown and crispy.
  • Bleaching/White Patches: Severe light burn can cause entire sections of leaves to turn white or very pale yellow, as chlorophyll is destroyed.
  • Affects New Growth: Symptoms are most prominent on the top canopy and new growth directly under the light.

Light Burn vs. Nutrient Burn

Light burn usually affects only the top leaves directly under the light, while nutrient burn (excess) typically shows crispy tips across the entire plant, often with very dark green leaves.

What Under-Lighting & Stretching Looks Like:

Insufficient light leads to weak, leggy plants as they "stretch" to find more light.

  • Stretching: Long internodal spacing (distance between sets of leaves), thin stems. Plants appear tall and spindly.
  • Pale Green/Yellow Leaves: Overall lighter green color due to insufficient photosynthesis.
  • Slow Growth: Significantly slower development compared to adequately lit plants.
  • Small Leaves: Leaves may be smaller than expected for the plant's age.