Ingredients for Good Coral Growth and Color

Ingredients for Good Coral Growth and Color

by Orphek

Light, Coral, and Photosynthesis

Many factors can affect coral growth; lighting, water temperature, feeding strategies, and water chemistry all have an affect coral growth and their appearance.  Proper lighting is one of the most important ingredients for successfully growing corals in a reef aquarium. The Zooxanthellae that live in coral tissue depend heavily on specific types of light energy to flourish in a symbiotic relationship with the host coral.  The Zooxanthellae provide food for the coral, and in return the coral provides protection from would be herbivores.  The lighting we provide for the reef aquarium must closely mimic the wavelengths and intensity found on the reefs to offer the same benefit to the corals as in their natural habitat.



There are some properties of light that should be considered when one wishes to successfully maintain and grow corals.

Lumens, PAR, and Wavelengths

A Lumen is a measure of the total amount of visible light emitted by a source.  Luminous flux differs from power or radiant flux in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all light emitted, independent of the eye's ability to perceive it. The more lumens, the brighter or more intense the light looks to the human eye.  A Lumen meter can be a useful tool for determining when lamps are getting old and need to be replaced, but for reef systems, a PAR (Photosynthetic Available Radiation) measurement is much more useful as most affordable lumen meters only measure the intensity of wavelengths up to 580 nanometers.  PAR meters will measure the entire spectrum visible to the human eye which is between 400 to 700 nanometers.  This is more accurate considering that corals respond best to wavelengths between 400-550 nanometers and 620-700 nanometers.  These wavelengths are called PUR (Photosynthetic Useable Radiation), and this is the most desirable spectrum for growing corals.  You can see by the spectrograph below, that our LED systems mimic this PUR spectrum very well.  The chlorophyll A and B is finely tuned to provide peaks in those wavelengths which accelerate photosynthesis thereby yielding a higher production of the food source corals require for accelerated growth.


LED spectrum chlorophyll A and B for growing corals

Light is energy, and travels in light waves. The wavelength of light is measured in nanometers, with violet and blue at the lower end of the visible spectrum (400-470 nm) and the red is at the higher end (at around 700 nm).  Wavelengths below 400 nanometers are considered UV or ultra violet.  Above 700 nanometers light is considered infrared. The color spectrum is very important for coral growth in your aquarium because certain wavelengths are more beneficial to coral than others.

Corals found in shallow reefs and tide pools receive a greater portion of the light spectrum and intensity of natural sunlight because there is not enough water to significantly filter the light (water absorbs certain wavelengths of light more readily than others). Blue light penetrates the deepest and that is why the water appears bluish at deeper depths. Corals found in deeper parts of the reef depend on more of the blue spectrum and less intense light.

Light penetration in seawater at different wavelengths

Light penetration in seawater at different wavelengths

The Orphek PR-156 LED aquarium light is designed to penetrate over 48″ (122cm) so that corals can be illuminated effectively in deeper aquariums without the need for metal halide or HQI lamps which run hot, use much more energy,  add heat to the water, and generally need replacing every 8 months.

Temperature

Zooxanthellae are not very adaptive when it comes to water temperature; they do best at temperatures between 23-28 C (73-82 F). These algae also need a good amount of light which is why shallow coral reefs are only found in tropical clear waters where temperatures do not fluctuate too much during the year. In the summer, temperatures sometimes get above 30 C (86 F), causing the Zooxanthellae to die off. As a result, the corals expel these symbiotic algae. This is called bleaching, and it is now a common process which occurs on many coral reefs.

Global warming has caused summer temperatures to become higher, and for longer periods of time. The corals and the Zooxanthellae have difficulty in adapting to this fast changing climate. It is therefore important that we try to slow down climate change by reducing the amount of greenhouse gases we produce.  Metal halide and HQI (High Quartz Iodide) light systems that are used on deeper aquariums generate high heat and can rapidly change the temperature of the aquarium without a means of cooling the water.  Our LED systems reduce heat by a large margin and eliminate the extra cost of energy needed to drive traditional lighting systems.  The high cost of chillers which are used to control the temperature of the water adds another expense to the system.

By choosing an Orphek aquarium LED lighting system, you will spend less money to maintain the proper temperature of your aquarium and eliminate any chance of coral bleaching due to elevated temperatures. Basically this means that by choosing an Orphek aquarium LED lighting system, your corals will grow faster, and their colors will be more colorful and more intense!

Additives for Enhancing Coral Growth and Color

Orphek’s lab is always experimenting with lighting and additives to achieve good coral growth rate as well as coloration.  No expense is spared in conducting these experiments as we wish all of our clients can have the same success we witness in our lab aquariums.

Although Orphek LED lighting is the most important factor for coral growth, additives must also be added to replenish the elements that are absorbed by the corals.  Without these elements, growth will be very slow or even cease with some corals.  Calcium and magnesium are the two most important elements to maintain and they must be kept at a three to one ratio. A calcium level of 400-450 ppm and a magnesium level of 1200-1300 ppm should be your target goal.  If magnesium levels are low, corals have difficulty in absorbing the calcium they require.  For example; If we have a calcium level of 400 ppm  but magnesium is only at 600 ppm  only one half (200ppm) of the calcium present will be available for the corals to absorb.  This is why magnesium is added to medications used to treat Osteoporosis in humans.

The medication contains calcium and in order for the body to absorb it, magnesium must be present in the same three to one ratio.  Calcium and dKH are intimately related, one can affect the other.  Keeping dKH levels at 7-9 is highly recommended.  Too high a dKH will cause calcium to precipitate out of solution.



Strontium levels in seawater are 8.1ppm and are just as essential for the growth and well being of reef building corals as calcium.  Strontium is supplied to the corals with the help of the zooxanthellae that live symbiotically within them.  Dosing this element on a weekly basis is recommended.



Potassium levels in seawater are 392 ppm and are an important component of aragonite.  Potassium is the mineral secreted as skeletal material by corals and other reef building marine organisms and is complexed into pigments that enhance blue coloration of some species of small polyp stony corals (SPS).  This element increases the color in colors when dosed regularly.

Ferrum (iron) is a minor trace element present in seawater at 0.0034ppm.  Iron is utilized in the transport chain within the chloroplasts, and is therefore required by photosynthetic organisms for continued functioning and health. In marine aquaria, these organisms include macroalgae, calcareous algae, and the symbiotic zooxanthellae that reside within the tissues of reef building corals, and also utilized by clams, and some sponges.  Supplementing iron at a higher level (.05-.10 ppm) than found in natural seawater enhances growth but exceeding this level is not recommended.  This supplement is particularly useful in aquariums utilizing a refugium with a mud substrate such as Miracle Mud.

Foods for corals are widely available and in many forms; liquids, powders, and live foods.  Most corals derive much of their food requirements through photosynthesis whereby the zooxanthellae that reside within their tissue provide the food source for them.  This food source alone, and in captive systems, is not enough nourishment to grow coral.  Although it will keep coral alive, other food sources are required to obtain a reasonable growth rate and good coloration.  I will provide a link to an article written by Bob Fenner titled “Stony Coral Feeding in Marine Aquarium Use.”

http://www.wetwebmedia.com/corlfeeding.htm



We recently asked users of Orphek LED products for their tips on growing corals and have placed a few responses below.

“My advice to anyone is first to get your nitrate and phosphates to undectable levels. Preferably using a Hanna Phosphate checker to measure and ensure your phosphates read 0.00ppm. I dose Lugol's iodine solution daily, every 4 days I add Brightwells Potassium powder. You need to though watch for signs of overdosing, for this I keep an eye on my yellow acro which will get a green shine if too much Iodine is being added. It's best to dose and visually learn these tell tale signs so as to strike a happy medium between your dosing regime and you corals. The other additive I use now and then, again works best when your nutrient levels are low and phosphates are undetectable  is to add KZ Zeospur. But do use sparingly at first, as it can cause damage if applied incorrectly. If corals look too pale, adding KZ Pohls Extra, will help with the enrichment of colors. Amino acids are also a good additive especially for nutrient starved systems, but again, will only add real value if your system is devoid of nutrients where you corals start have that pale starve look.

I believe then that, once u have your water parameters right, then will lighting start to add the real benefits to your SPS coloring up, much more than that of a system that is carrying nutrients and elevated phosphate levels.
Regards

Adrian”


sps under orphek led lighting
























“Happy to give you some tips.

Establishing an abundant and healthy Symbiodinium population is essential for maintaining deep colours in corals. This can be achieved by avoiding conditions which can cause bleaching (high temperature, high light (especially UV), pollutants, disease outbreaks, etc), but by also building resilience in the coral-algal symbiosis. Photosynthesis in the algal symbionts is essential for providing the animal host with an autotrophic source of nutrition. Up to 95% of the photosynthate produced by the symbionts is translocated to the animal, and this is the reason why coral reefs are so abundant in nutrient waters of the tropical oceans. However, by supplementing the energy produced through photosynthesis, by providing a heterotrophic food source, the health of both partners in the coral symbiosis is improved. Heterotrophic food sources, such as brine shrimp, are captured by the coral polyps and once digested supply a rich source of organic compounds of nitrogen, phosphorus as well as fatty acids, which are not available through autotrophic nutrition. In corals which are grown under optimal irradiance conditions and supplemented with heterotrophic food, colours are much deeper due to the more abundant population of Symbiodinium and/or the greater concentration of photosynthetic pigments (chlorophyll and peridinin) per algal cell. This colour is also sustained during periods of mild or short-term stress as the coral is more resilient against bleaching. This is one suggestion on how coral colour can be improved for those who presently only supply an autotrophic nutritional food source.

Cheers,

Ross”

Orphek LED revolution for Reef aquarium

Orphek LED revolution for Reef aquarium

This is Part three in a series of articles and in this article we will focus on the LEDs we use, particularly our new revolutionary 18K white LED.


First we will explain what LEDs are and how they work.  A LED is not a miniature light bulb, it is actually a semiconductor much the same as those used to power our speakers in our stereo systems.  Instead of generating power or wattage, they generate light.  A LED is actually the simplest form of a diode which makes these semiconductors easy to work with as they only have two leads.  LEDs are specially constructed to release a large number of photons outward. They are housed in a plastic bulb that concentrates the light in a particular direction.  Most of the light from the diode bounces off the sides of the bulb and travels on through the rounded end so there is no wasted light.  Metal halides and fluorescent lamps waste a lot of light since the light travels in all directions and must be redirected by reflectors into the aquarium.  LEDs have several advantages over metal halide and HQI lamps. For one thing, they don't have a filament that will burn out, so they last much longer. And, their small plastic bulb makes them a lot more durable.  But the main advantage is their efficiency.  In conventional incandescent lamps the light production process involves generating a lot of heat. This is wasted energy because a large portion of the available electricity isn't going toward producing visible light. LEDs generate very little heat, and a much higher percentage of the electrical power is going directly to generating light which drops electricity demands considerably.  Watt for watt, LEDs output more lumens of light than metal halide, HQI and fluorescent. Light emitting diodes also have a higher luminous efficacy than other types of aquarium lamps.  For example, an EvoLux LED produces 76.9 lumens per watt compared to an incandescent bulb's 17 lumens per watt.  Another huge benefit is that they last; LEDs can have lifetimes of 50,000 hours or more.

 
Orphek PR156xp

Manufacturers of Aquarium LED fixtures are increasing on a weekly basis and it certainly appears that LED lighting over our aquariums will be the norm in a very short time.  Most of these companies use off the shelf SMT (Surface Mount Technology) diodes, and in some cases such as LED strip lights, LED ribbon strips are used.  By using off the shelf LEDs, companies are limited to wavelength and/or Kelvin temperatures so the need to add different color diodes is necessary to produce the desired color or effect they want, and to mimic the PUR wavelength which is so necessary for proper coral growth.  Red, blue, green, and yellow are usually added to achieve the desired effect but these colors also have lower lumens per watt than the white LEDs which lower the total lumens per watt of the entire fixture while still not generating a good PUR spectrum.  With Orphek LED lighting, the white LEDs are custom made to Orphek specifications with the correct amount and type of phosphors so that blue lighting can actually be obtained from white LEDs which have the highest lumens per watt.  Because of this breakthrough, Orphek can reduce the amount of colored LEDs other manufacturer’s use that are necessary to obtain the blue effect which is a necessary wavelength in the PUR spectrum.  There is a big difference in lumens per watt between blue LEDs and white LEDs. If you look at the LED make up of Orphek fixtures, this can readily be seen.  The graphic below shows the diode makeup of the 100 LED multi chip used in the DIF 100XP.  As you can see, there are only 10 diodes used (red and orange) for enhancing the color of the corals.  Our expertly designed and produced lenses are made from optical quality glass to ensure the light from the few colored diodes that are used, is evenly spread throughout the aquarium.  There are no dead spots.

Orphek LED DIF 100 XP

60 – 18k White

10 – 450nm blue

10 – 430 nm actinic

10 – 410 nm UV

6 – 590 nm orange

4 – 660nm red

If you look at Cree XP-G LEDs on their web site, the white diodes are only available in cool white or warm white so much more blue must be added to achieve the desired color.  For example, the DIF 100XP which does not use Cree LEDs, but uses our own proprietary 18K white diodes.  Our LEDs have no model numbers; you cannot order these LEDs from a LED company for DIY projects. Orphek uses several American LED companies to produce their diodes to their exact specifications.  We have never used cheap Chinese made diodes in any of our products.  With Orphek revolutionary technology we have designed the first white 18K LED that actually produces blue with no appreciable loss of lumens per watt.  The benefits of this new diode technology are high lumens per watt as well as a high CRI index.  There is not another aquarium LED lighting manufacturer that can state this.   Our fixtures are very low in the 550-620 nm range which is the range nuisance algae and cyanobacteria thrive on.  In the graphic below you can see the high amount of light being generated by the Cree 7000K LED in the 550-620 wavelengths.  Compared to Orphek white LED, this is very high and will contribute to nuisance algae and/or cyanobacteria.

Orphek 16K LED Vs Cree LED



A Word about PAR and PUR

The term PAR means Photosynthetic Available Radiation.  This range covers the light spectrum from 400 to 700nm.  Not all of this range is necessary, or even recommended for corals and clams.  The term PUR means Photosynthetic Usable Radiation and is the spectrum corals and clams best respond to.  With LEDs, we cannot waste energy providing unneeded wavelengths, but focus our energy in the needed spectrum which falls between 400-550 nm and 620-700 nm.  In this regard we can provide high intensity lighting in these needed wavelengths.  With other forms of lighting, a high PAR is needed to grow corals because there is much energy wasted in unneeded wavelengths so the PUR wavelengths available must be amplified to provide the light energy needed.  With Orphek LEDs, the spectrum is carefully tuned to the PUR wavelengths and a PAR reading of 100 at the bottom of the aquarium will provide enough upward gradients to grow the corals and clams we generally keep in our reef tanks.  The recent review of the DIF 50XP will show PAR levels at various distances.

Because of the quality of LEDs used in all Orphek fixtures, diode failure is nearly non-existent.  This is quite impressive considering that we have installed over 100,000 LEDs in our fixtures over the last two and a half years.



Orphek R&D department is always experimenting with different types of diodes and electronics to further improve our products.  As an example, the current PR 156 fixture uses completely different diodes than the original model did.


Reef Aquarium with Orphek LED lighting

The appearance of the corals is stunning under our 18K white LEDs.

Before buying any LED fixture, compare their spectrograph with ours.  Is their spectrograph high in reds and yellows, do they use green LEDs for effect which have no real benefit for growing coral.  What are their PAR/PUR readings compared to ours, and especially look at these figures at deeper depths where Orphek excels in high PAR readings.  Be aware that a high PAR reading means little unless it is measuring the light in the PUR range, the range corals best respond to.  To be specific, this range falls between 400-550 nm and 620-700 nm.

 

Our new multi chip using 60% 18K white LED diodes duplicates the PUR range perfectly.

What are the benefits of using Orphek LED Lighting;

• Cooler running with our exclusive extruded aluminum heat sinks


• Efficient Meanwell drivers


• High PAR/PUR


• High 450 nm peak obtained with minimal use of blue diodes


• Long diode life, diodes are never overdriven to obtain high intensity


• Choice of lenses


• Custom diode makeup at no extra charge


• Revolutionary 18K LEDs not found in any other LED fixture on the market.


• Orphek quality, reputation, and customer service