For LED lights in the 90 Watt range, often considered a sweet spot for common aquarium sizes, you will typically need one light for every 24 inches of tank length.
Determining LED Needs Based on Tank Length
When selecting LED lighting for your reef tank, the amount of light required is a critical factor for the health of your corals and other inhabitants. While various metrics exist, a practical guideline, especially for popular LED fixtures in the 90 Watt range, is based on the length of your aquarium.
According to guidance for lights in the 90 Watt range, which are great for 24" to 48" long aquariums, the rule of thumb is to use one light for every 24 inches of tank length. This suggests that a single 90W-class fixture is designed to effectively cover a footprint of approximately 24 inches in length.
Applying the 24-Inch Rule
To determine the number of these specific 90W range lights needed for your tank, simply measure its length and apply the guideline:
| Tank Length | Number of 90W Range Lights Needed (approx.) |
|---|---|
| Up to 24 inches | 1 |
| 25 to 48 inches | 2 |
| 49 to 72 inches | 3 |
| 73 to 96 inches | 4 |
Note: This table illustrates the guideline of needing one light per 24 inches of length for fixtures in the 90 Watt range.
Practical Considerations
Utilizing this guideline helps ensure adequate light spread across your reef tank. For instance:
- A 48-inch long tank would typically require two lights from the 90W range to achieve sufficient coverage along its entire length.
- A 72-inch long tank would likely need three lights following this rule.
While the 90 Watt range is highlighted as effective for 24" - 48" long aquariums, the core principle from the reference is the coverage area: one light covers roughly 24 inches.
It's important to measure the internal length of your aquarium accurately to apply this guideline. Positioning the lights correctly over the tank will help maximize their coverage and performance.
