How to Color Your Corals (Coral Coloration)

Everyone wants brightly colored corals in their aquarium. Quite often corals fade in coloration and maybe even change colors entirely. There are several factors that can affect the coloration of your corals, including lighting, trace elements and nutrients.

Coral coloration can change in different lighting conditions. The biggest change that lighting makes on coral color is with our visual perception of the coral rather than the true color of the coral. Our eyes see florescent coral colors such as greens and reds as far brighter under blue light such as the light from an actinic lamp. White light from 10,000k lamps makes non florescent purples and blues look better and the combination of red and blue light found in purple bulbs can make pink corals look more pronounced.

Pay attention to what color the light is at the store where you purchased your corals from. If your lighting is a different color, then the coral you purchase is bound to look different. Swapping the bulbs out in your florescent or metal halide fixture can radically change the color of your corals. If you have an LED light such as a Kessil you can change the color of the light to where you like the way the corals look.

Lighting intensity can also change the coloration of your corals. Corals produce color pigments to protect themselves from the sun. This is similar to how our bodies produce dark color pigment to protect us from the sun. When people are exposed to the sun they get darker, but when corals are exposed to the sun they get more colorful. If the corals in your tank are minimally lit they will not be as colorful as they could be. Using a brighter light is almost always a good thing for coral coloration (though, keep in mind that too much light can kill corals).

how to color your coralsNutrient levels can dramatically change the coloration of corals. In general, corals that are grown in higher nutrient levels look darker and corals in lower nutrient levels look pale. In a study done at Wageningen University in The Netherlands researchers studied the effects of nutrient levels on corals. Corals were taken from the same mother colonies and then grown out in different nutrient conditions but with the same lighting, flow, and maintenance.

You can see in the included picture how extreme the difference in color was. This illustrates just how important nutrient levels are when it comes to coral color. If your nitrate and phosphate levels are on the higher end of acceptable then your corals can often look brown. On the other hand, if you have absolutely no nitrate and phosphate then your corals can look bleached. Shoot for nutrient levels of between 1-5 ppm nitrate and .03-.05 phosphate for optimal color. If your corals start turning brown consider using carbon or a phosphate remover such as Two Little Fishies Phosban. If your corals start to turn pale consider adding amino acids and coral foods.

Trace Elements
Trace elements are elements that are present in seawater but only at very low levels. These elements do not typically have huge effects on coral growth or basic health, but they can be very important to achieving good coral coloration. The first step in deciding whether trace elements need to be adjusted in your aquarium is measuring their levels.

There are test kits that measure some trace element levels, but they are often difficult to use and not very accurate. A better method is to use an ICP Water Analysis Kit to have your water professionally tested using a laboratory grade machine. Simply open the kit and fill the included vial with aquarium water. Mail the vial using the included envelope to ICP in Colorado for testing. You will then be emailed your results. These tests cover 33 different parameters and then compare the results to natural sea water levels.

Once you get your results back you can work to make sure that all the elements are at the proper levels in your aquarium. If you donít want to test then you can try to add elements to increase certain colors. Just understand that overdosing these elements can be far worse than leaving them alone.