Plan brighter tanks using loss-aware lighting targets and practical inputs at home. Compare setups, estimate fixtures, manage energy, and balance growth with comfort daily.
These sample scenarios show how the estimator responds to depth and livestock goals.
| Tank (cm) | Profile | Fill | Clarity | Target PAR | Typical lm | Typical W |
|---|---|---|---|---|---|---|
| 60×30×36 | Freshwater (low) | 90% | Typical | 25 | 2,500–4,000 | 18–30 |
| 90×45×45 | Freshwater (medium) | 90% | Typical | 50 | 7,000–11,000 | 45–85 |
| 120×50×50 | Reef (LPS) | 95% | Very clear | 120 | 18,000–28,000 | 110–200 |
| 120×60×55 | Reef (SPS) | 95% | Very clear | 200 | 28,000–45,000 | 170–320 |
Real fixtures vary by optics, spectrum, and layout.
For reefs, PAR is the primary metric; lumens are used here only to estimate fixture output and energy.
If algae appears, reduce photoperiod before increasing intensity.
Use lighting goals to match livestock needs and tank depth. This guide explains how the calculator turns a PAR target into lumens, fixture count, and energy, while accounting for common real‑world losses.
Light is a controllable input that shapes growth, coloration, and algae pressure. Overshooting targets often causes instability, while undershooting slows plants and dulls displays. A measurable target helps you make small, repeatable adjustments instead of guessing.
Typical starting ranges at the substrate are: 15–25 for fish‑only viewing, ~25 for low‑light plants, ~50 for medium planted tanks, ~80 for high‑light plants, ~80 for soft corals, ~120 for many LPS, and ~200 for SPS reefs.
Many fixtures list lumens and watts, not PAR. The model uses a common white‑light approximation, lux ≈ 54 × PAR, then computes lumens arriving at the target plane as lumens = lux × footprint area. Spectrum and optics still matter, so treat lumens as an estimate.
Depth reduces intensity through absorption and scattering. The calculator uses an attenuation term Twater = exp(−k×depth), with typical k values of 0.15 (very clear), 0.22 (normal), and 0.30 (tinted). Deeper tanks and higher k raise required fixture output quickly.
A glass lid can reduce delivery by about 8% when clean, and more when salted or fogged. Mesh screens are often nearer 3%. Higher mounting increases spill and lowers delivered light. These small losses compound with depth, so accounting for them improves sizing accuracy.
Utilization (often 70–90%) captures shading from hardscape, reflectance, and how evenly the beam covers the footprint. Two smaller fixtures commonly produce better uniformity than one hotspot. Better spread can improve coral placement and reduce plant shadowing.
Power is estimated from lumens and LED efficacy (commonly 100–180 lm/W). Daily energy is kWh/day = (W/1000) × photoperiod. This makes it easier to compare fixture options and forecast monthly electricity use under different schedules and dimming plans.
Start at the low end of the target range, then increase slowly while observing livestock. For reefs, use dimming to acclimate and avoid sudden jumps. For planted tanks, balance light with nutrients and CO₂. Measure at multiple points when possible, and adjust in small steps.
Measure, adjust slowly, and keep schedules consistent each week.
Lumens are weighted for human vision, not coral response. Use PAR for accuracy. Lumens here help estimate fixture output and power when PAR specs are unavailable.
Start with 80–90% for well-covered footprints and multiple fixtures. Use 70–80% if you have heavy hardscape shading, narrow optics, or a single point-source light.
Glass reflects and absorbs some light, especially when it gets salt spray or condensation. Even modest loss means the fixture must output more lumens to hit the same target at depth.
If you plan to run at 60–80% most days, add headroom so the fixture is not maxed out. Increase intensity gradually over weeks to reduce stress and bleaching risk.
A common starting point is 8 hours daily. Planted tanks often run 7–9 hours, reefs 8–10 hours. If algae increases, reduce time before raising nutrients or intensity.
Clarity changes the attenuation coefficient k. Higher k means more scattering and absorption, so less light reaches the bottom. Filtration, carbon, and maintenance can improve clarity.
Use it as a planning estimate. Real performance depends on optics, spread, mounting height, and spectrum. When possible, verify with PAR readings at several points across the tank.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.