Reef tank lighting schedule - What is the ideal spectrum program for your LED lights? | Reef FAQs
The controllability of LED lighting gives us the power to adjust spectrum and intensity but sadly most of the manufactures don’t bother to instruct users how to make these adjustments without risking the lives of coral.
The slide and pray approach is becoming all to common and, unfortunately, the results are often slow growth, poor coloration and even mortalities.
We have decided it is time to show all of you how to program your LED lights through our next ReefFAQs videos series and our focus in this episode will be sharing our unique solution to tuning spectrum.
Stability is king
Some reefers get lucky, some are just intuitive guessers but many fail when attempting to dial in an LED light using the custom controls.
Luckily, you don’t need to be a marine biologist to get this absolutely perfect and have a successful reef tank. Through the entire process the most important factor is stability, corals are amazingly adaptive creatures if you just give them a chance.
The most critical message is set the spectrum to the best of you your ability and then leave it alone for 9 - 12 months if not permanently.
If you are making changes every week, month or even every few months, don't be surprised if it shows with negative results in your tank. That is one of the main reasons why T5 and metal halide bulbs produced such positive plug and play results. You only change the bulbs out every 12-18 months, stability is king.
How LED lights create a usable spectrum
Corals have adapted over millennia to specific light spectrum ranges and they use specific wavelength peaks more efficiently than others. The wrong spectrum can cause major metabolic changes like loss or change of color, poor growth and even death.
The chart from Orphek above helps visualize how this works. You can see the color of the light on the bar below and the corresponding wavelength measured in nanometers. Then above that you can see the exact peak on this spectrum at which the various types of chlorophyll and carotenoids within corals are most efficient.
LED color channels create very specific color spectrum peaks that when blended together correctly they create the desired spectrum mix for optimal photosynthesis.
For example, the spectral graphs above show our measurements of all the individual color channels of the Aqua Illumination Prime LED.
This is what it looks like when they are all blended together to create a cohesive full spectrum mix that we created to match the EcoTech CoralLab SPS AB+ mix.
How well various LED lights are able to achieve this blending is up for debate but it is obvious the ones that are making a strong attempt by being transparent with what they are doing and why they do it.
Here is a spectral graph of the Orphek Atlantik LEDs and how it overlays with the light and energy requirements of many corals. The jagged magenta line shows the Atlantik LED output while the solid red, green, black and blue lines are various wavelengths that corals use.
Go with the best and ignore the rest
Most of us don’t own a multi-thousand dollar spectrometers required to measure spectrum and custom blend all of the colors perfectly.
By far, the best way to achieve this is rely on the manufacturer of the light. It is safe to say most reefers want to just set the light for optimal coral health. Considering these lights are designed for reef tanks, it is not too much to ask.
Giving reefers the ability to adjust spectrum past that point is fine, but it should probably be hidden away with large warnings and caution signs informing you that treating it like a toy and making frequent changes is a one way ticket to brown town.
Kessil has done this well by locking down the critical spectrum peaks for coral health and allowing changes to less critical peaks for visual appeal which is what they call Kessil Logic.
Ecotech Marine CoralLabs SPS AB+ spectrum mix is based on research and results in high demand environments like coral grow out facilities where maximizing growth and coloration equals maximum profits.
Red Sea followed suit with the ReefLED and its Reef Spec which has locked down an optimal spectrum based on their own research for optimal metabolic function within corals but still allows some adjustment to accomodate personal preferences.
Any manufacturer that clearly outlines the right mix for a reef tank or refines it further with various spectrums specifically for SPS, LPS, etc. is likely a trustworthy source and it is best to utilize those spectrum settings to achieve results. Something reefers should seriously consider when shopping for lights.
Ignoring this and choosing something less expensive then attempting to tune it yourself will likely show within your corals and various other aspects of the light itself.
How to create the best spectrum
Follow the recommendations in our BRStv Investigates episodes about specific LED lights. In most cases we make spectrum blending suggestions using a spectrometer to measure and adjust the light to match the most successful spectrum mixes. This is a good resource to check out the spectrums an LED light is capable of producing and how to mix the color channels to achieve the desired goal.
If there are limited resources available on the light you selected, you will just have to make your best guess short of using a spectrometer yourself which is extremely costly and time consuming.
It is widely agreed that the most beneficial wavelengths for coral growth and health are what the human eye perceives as the blue spectrums.
For that reason most reefers will turn those UV, violet and blue spectrums to the maximum and then add in white until it looks appealing.
The red and green are used sparingly just because the reefing community is undecided on their value. Red and green tend to also contribute heavily to creating the disco ball effect because those individual colors are easy to see shooting all around the tank.
Once you get the color the way you like it, you will likely need to adjust the overall intensity. Some LEDs like Kessil and EcoTech Marine have an intensity slider that will adjust intensity all of the color channels in ratio but some require this be done individually per color channel.
Using a PAR meter is really the only way to tell when you have hit the desired intensity which we offer for sale or rent.
Is there a better way?
Many in the community are also willing to show their results from the exact light you are using and settings. From our experience, the best results are from emulating successful reefers before you.
Spectrum blending - Avoiding the disco ball effect
T5 and metal halide bulbs offered a uniform spectrum but LED’s need to use a slew of different LED peaks to emulate a full spectrum, uniform light. It may look blended visually, but if you look closely in the tank you can often see the individual dots or lines of white, blue, green and red shooting around your sand bed or on the rock work. This is what hobbyists refer to as spectrum hotspots and is a direct result of a poorly blended spectrum.
This is intensified by the ripples on the surface of the water catching the individual LED spectrums, magnifying and then shooting that light around the tank. I think the jury is still out on how much this matters but when given the choice, 99.9% of reefers would NOT prefer to see this in their tank.
LED manufacturers are solving this problem a few different ways. Kessil’s approach of putting all the LED diodes under a single lens does a solid job of blending all of the individual spectrums which you can see for yourself in our BRStv Investigates episode in which we looked at Kessil’s A360X LED performance.
A diffuser is also an option which is a sheet of diffuser material over the LED layout for the purpose of blending the colors together. This will reduce the intensity to a certain degree but comes with performance advantages, specifically the reduction of spectrum hotspots . EcoTech Marine takes advantage of this technique with the optional Radion Diffuser. We have a great video that shows you how to install it and how well it works.
Changing spectrum throughout the photoperiod
No one really knows definitively whether the effects are beneficial but we do know that changing spectrum is certainly not required for success.
If you want to change the spectrum for visual appeal throughout the day, consider doing it similar to the way Kessil logic suggests. Reduce the whites during ramp up and ramp down and leave all the blues the same.
World Wide Corals changes the spectrum throughout the day from white to blue with very minimal ramp times. The mindset is turbocharge the photosynthesis in the morning and then let it slow down throughout the day. We go into detail about the process in our SPS reef tank lighting made simple and stable. - The BRS/WWC System Ep11 - BRStv so check it out to learn more.