Base Light Tier describes the general light intensity range a plant is expecting, using PPFD ranges rather than vague and subjective terms like “low” or “bright indirect” light. It sets the expectation for where the plant can maintain a positive energy balance, not the absolute minimum or maximum it can tolerate.
The base tier reflects the plant’s natural light adaptation and helps explain why some plants coast along in typical rooms while others slowly decline without ever looking dramatically stressed.
Base Light Tiers used in plant profiles:
Tier 1 (50–150 µmol/m²/s) — Plants adapted to deep shade or very low indoor light. Growth is slow, energy margins are narrow, and changes happen gradually.
Tier 2 (150–300 µmol/m²/s) — Plants adapted to shaded understory conditions with consistent, usable light. This is where many common flowering and foliage plants maintain stable growth indoors.
Tier 3 (300–500 µmol/m²/s) — Plants adapted to brighter indoor conditions or filtered sun. Growth rates increase and water and nutrient use become more predictable.
Tier 4 (500–800 µmol/m²/s) — Plants adapted to strong light indoors or prolonged bright exposure. Energy availability is high and growth is rapid when other factors align.
Tier 5 (800–1200 µmol/m²/s) — Plants adapted to very high light, often transitional to outdoor sun conditions. Indoor use requires careful balance of water and nutrition.
Tier 6 (1200+ µmol/m²/s) — Full sun or outdoor high-light plants. This tier is included for context and comparison rather than typical indoor growing.
In short, Base Light Tier tells you where a plant naturally “lives” on the light intensity spectrum, helping you understand whether the available light supports steady growth or creates a slow, invisible energy deficit over time.
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