What Is the Best Lighting Schedule?
When keeping photosynthetic animals in a reef tank it is critical that you have an optimized light schedule to mimic the natural light cycle these animals receive in the wild. This allows corals and clams to properly photosynthesize and live a long happy life in your aquarium. The facts are, the right light schedule is equally as important as providing the right spectrum and intensity for your tank's inhabitants.
It Doesn't Have To Be Complicated
Modern reef tanks lights, primarily LED lights, have been developed to give users complete control over the spectrum and intensity which can make it seem far more complicated than it has to be. In days past, you simply chose the appropriate bulb(s) for your tank and then used a timer to turn them on and off for a specific amount of time each day. Just like the sun rises and falls like clockwork, each and every day. There was no tinkering with the color or intensity, your bulbs were either ON or OFF.
Nowadays, we can program very custom light schedules and change both the color and intensity at any point throughout the day. This versatile control is exactly the reason lighting has become so much more complicated compared to days past. The downfall here is hobbyists can tinker with the lights to their demise or simply have trouble deciding on the appropriate light schedule. The reality is, a clear path to success can be found so long as you don't tinker with the light settings and follow the guidance of those who have experienced the same level of success you desire.
How To Setup Your LED Light
1) Pick A Proven Spectrum - Most LED lights come with presets that are optimized for coral reef aquariums. You just have to choose whether you want it to look bluer or more white in the tank. Once you decide, it's best not to change things up or else you will stress out your corals. Stay away from using the color sliders and trying to make your own custom spectrum blend unless you have the experience necessary to create a successful spectrum.
2) Use 1:8:1 Ratio - This refers to the length of time you run the light. While there is not a definitive or exact time frame used by all hobbyists, it will always be somewhere within the 8 - 12 hours of total ON time each day. Exactly like the sun. This also includes a short ramping up to the maximum intensity and ramping down to zero intensity at the beginning and end of each day to mimic sunrise and sunset. The following 1:8:1 ratio will be a successful approach over any reef tank.
- 1-hour ramp up to maximum intensity to start the day
- 8-hours of running the light at full intensity
- 1-hour ramp downtime at the end of each day
3) Pick The Right Intensity - This is how bright the light runs each day during the 8 hours of maximum intensity and is very important. Not enough light and the coral cannot survive, too much light and you can stress or burn the corals. You must use a PAR meter to measure the light throughout your aquarium. The goal is to achieve the following numbers throughout as much of the tank as possible based on the type of coral you plan to keep.
- Soft Coral and LPS: 75 -150 PAR
- SPS Corals: 200-350 PAR
When using the PAR meter, you will likely test the lower numbers towards the bottom and higher PAR numbers towards the top. Once you have adjusted the intensity of your LED light to hit the PAR numbers you need, you are all set. You will never need to come back and change ANY of these settings.
When setting up your light remember this - "Just because we can tinker with it, doesn't mean we should!" Making changes to light settings is the #1 reason new hobbyists have trouble with their lighting.