Lighting
Table of Contents
Aquarium lighting this multi-tier reef system was perhaps the most time consuming, but also the most fun and rewarding from the standpoint of knowledge. Overall, aquarium lighting is a very controversial issue, with a multitude of products the consumer seeking aquarium lighting often finds himself or herself confused. I had some experience with aquarium lighting, but nothing to the scale of this new reef aquarium system.
My 40 gallon reef system was illuminated by six 110w VHO bulbs. Prior to this endeavor I did not have the opportunity to experiment with different lightingcombinations, in fact the aquarium hood I designed and built was my first attempt at aquarium lighting.
I figured this was my chance to try anything I wanted and I welcomed this opportunity. I wanted to try to match the Kelvin temperature over each section of the coral reef in my reef aquarium, so I set out to illuminate them all differently. I wanted different wattage and different Kelvin temperature of the bulbs.
Starting with the lagoon, I ran two 5500k 175w Metal Halide bulbs; ideally they would have been much brighter like 400 watt Metal halides aquarium bulbs. At the shallow depth bright bulbs in the color spectrum would have caused allot of complications with nuisance algae. This forced me to use the 175w metal halides.
The back aquarium reef was one 10k 175w Metal halide; I would have liked to use something a bit bluer and a bit more intense. I went with the 10k, but I most likely should have gone with a 6500k metal halide. The back reef is a shallow area usually pretty flat.
The lower aquarium reef was a 20k 175w Metal halide. I did feel that was fairly accurate and a good choice for the aquarium setup. The upper reef a 14k 175w Metal halide and the aquarium reef crest used 2 175w 6500k Metal Halide bulbs. As time progressed I modified the lighting setup to increase intensity over than aquarium. By dropping the temperature with the chiller and increasing the PH and salinity to a lesser extent, I was able to ward off a large bit of the nuisance algae that would typically be associated with increased intensity over such a shallow reef aquarium system.
The Essential Guide to Reef Aquarium Lighting
Lighting in a reef aquarium isn’t just about making the tank look pretty. It’s a critical component of the ecosystem that supports the life of corals, fish, and other marine invertebrates. The right lighting can make the difference between a thriving reef and a struggling one. With advancements in technology and a better understanding of marine biology, the options and strategies for lighting a reef tank have evolved significantly. Whether you’re setting up your first reef tank or looking to upgrade your current setup, understanding the nuances of reef aquarium lighting can greatly enhance the health and beauty of your underwater world.
Understanding the Spectrum: Lighting Needs for Coral Health
The Role of PAR in Coral Photosynthesis
Photosynthesis in corals isn’t just a high school biology topic; it’s the essence of coral survival. The process relies heavily on photosynthetically active radiation (PAR), which is the range of light (400-700 nanometers) used by plants and corals for photosynthesis. For a reef tank, ensuring your lighting system provides adequate PAR across the entire tank is crucial, especially for SPS (Small Polyp Stony) corals, which are particularly demanding in light requirements. The intensity and quality of light, measured in PAR, can significantly influence coral growth and coloration.
Balancing Act: Spectrum and Intensity
When it comes to reef lighting, it’s not just about the brightness but the quality of light. The spectrum of light is paramount, with blue to ultraviolet wavelengths (380-495 nm) promoting better coral growth and fluorescence. The concept of PUR (Photosynthetically Usable Radiation) comes into play here, emphasizing light wavelengths that corals can efficiently use for photosynthesis. A balanced spectrum that mimics the natural sunlight penetrating the ocean’s surface is vital, with a mix of blue, white, and actinic lights creating not only an appealing visual effect but also a healthy environment for corals.
The Evolution of Lighting Technologies
From T5s to LEDs: A Technological Leap
The transition from T5 fluorescent bulbs to LED (Light Emitting Diode) lighting represents a significant technological leap in reef aquarium lighting. LEDs offer unparalleled control over intensity and spectrum, allowing aquarists to simulate natural light cycles including sunrise, sunset, and moonlight phases. This capability not only enhances the visual appeal of the tank but also supports the natural rhythms of coral and fish life. Furthermore, LEDs are more energy-efficient and have a longer lifespan than traditional T5s, making them a cost-effective and environmentally friendly option in the long run.
Smart Lighting: Automation and Customization
In the digital age, reef aquarium lighting has gone smart. Modern LED systems come with built-in controllers or app integration that allows for precise adjustments of intensity, color, and timing. This level of automation and customization enables aquarists to create lighting conditions tailored to the specific needs of their reef tank inhabitants. Features like weather simulation, cloud cover, and lightning storms add an extra layer of realism, providing both aesthetic pleasure and environmental enrichment for the tank’s ecosystem.
Lighting Strategies for Different Tank Depths
Shallow Reefs: Balancing Intensity and Spread
Shallow reef tanks, often referred to as lagoon-style tanks, require a careful balance between light intensity and spread. In shallow waters, corals are exposed to more intense sunlight, but in an aquarium setting, this needs to be moderated to prevent photoinhibition or bleaching. LED fixtures with adjustable intensity and wide-angle lenses can distribute light evenly across the tank, ensuring all corals receive the light they need without overexposure.
Deep Reefs: Penetration and Coverage
Deep reef tanks pose a different challenge: ensuring light penetrates to the bottom without losing intensity. This is where the power of LED lighting really shines, with options for narrow beam angles to focus light deeper into the tank. Supplementing with T5 fluorescent lighting can also help provide a more uniform light spread, ensuring lower-dwelling corals and invertebrates aren’t left in the dark. It’s a delicate dance of providing enough light for photosynthesis while maintaining a naturalistic and visually appealing underwater scene.
Conclusion
The art and science of reef aquarium lighting have come a long way, with advancements in technology providing aquarists with an array of tools to recreate the ocean’s complex lighting environment. Understanding the needs of your reef inhabitants, coupled with the right equipment and strategy, can lead to a thriving ecosystem that’s not only a joy to behold but also a testament to the wonders of marine life.
FAQs on Reef Aquarium Lighting
1. What is the best type of lighting for a reef aquarium?
The best lighting for a reef aquarium depends on the tank’s size, depth, and inhabitants. LED lighting is widely regarded as the most versatile and efficient option, offering control over intensity, spectrum, and photoperiod to meet the specific needs of corals and marine life.
2. How long should I keep the lights on in my reef tank?
The typical photoperiod for a reef tank is 8 to 12 hours per day, simulating natural daylight cycles. However, this can vary based on the type of corals and their specific light requirements. Using a programmable timer or smart lighting system can help automate this process.
3. Can too much light harm my reef aquarium?
Yes, excessive lighting can lead to photoinhibition or coral bleaching, where corals expel their symbiotic algae due to stress, leading to a loss of color and vitality. It’s important to adjust the intensity and duration of lighting according to the tank’s depth and the light needs of its inhabitants.
4. How do I know if my reef tank is getting enough light?
Observing coral health and behavior is a key indicator. Healthy corals should display vibrant colors and steady growth. Signs of insufficient light may include slow growth, color fading, or corals stretching towards the light source.
5. Is it necessary to change the spectrum of light over time?
Adjusting the spectrum can benefit corals by simulating natural changes in sunlight throughout the day and seasons, promoting natural growth cycles. Many advanced LED systems offer this feature, allowing for a dynamic and responsive reef tank environment.
