World Wide Corals 8 Coral Coloration Tips to Make Your Acropora POP!
WWC finds the best coral coloration in mature reef tanks with nitrates in the 20-25 PPM range which is quite high given traditional advice. Most hobbyists will strive to maintain nitrates in the 5-10 PPM range with the idea that higher nitrates give way to algae blooms. So which is best?
If you have a mature tank that is packed full of growing coral, you can safely increase nitrate and likely experience more vibrant coloration without causing algae blooms or water quality problems. In new tanks or maturing tanks with small corals, it is best to be conservative with your nitrates to avoid those pesky algae blooms.
2. Tiny Phosphates
Phosphate is a fickle beast in that too much is just as bad as none at all. Too much phosphate can instigate algae blooms but more importantly, too much phosphate inhibits the ability of the coral to create and deposit skeletal material meaning it cannot grow! No phosphate at all can starve the coral of vital nutrients; much like a plant that needs fertilizer (nitrogen, phosphorous, and potassium NPK) to grow.
The goal is to always have some level of phosphate without ever allowing it to rise beyond an acceptable range. This can be tricky and is only possible with frequent monitoring of your tank's phosphate levels using a reliable test kit. Most experienced hobbyists strive to keep phosphates below 0.1 PPM with 0.01 - 0.05 PPM being ideal.
Note, this is not like nitrates where you have more flexibility. Should you decide to boost nitrates, maintaining that low phosphate level is all that more important to avoid algae and maintain the health of your corals because the things we use to increase nitrate often contain phosphate as well. You will likely need to engage some kind of phosphate control like GFO or lanthanum chloride to keep phosphate under control while allowing nitrates to climb.
3. Balance Light & Flow
When growing SPS, most hobbyists place ideals around stable parameters, clean water, and high levels of light which are all very important. The missing link here is Water Flow in that the more light you have, the more flow you need to help those corals grow at accelerated rates.
Additionally, if you're on track to increase light and water flow in an attempt to accelerate coral growth, consider the role of nutrients. Corals expend nutrients to create the energy required to grow. Accelerated growth requires more energy which means more nutrient uptake. If results are not achieved with flow and light alone, increasing nutrients could be the key.
4. Amino Acids
It has been proven time and time again that the direct addition of amino acid solutions promotes better growth and coloration among corals in a reef aquarium. Amino acids are fundamentally the building blocks of protein and corals use protein to create tissue. Without amino acids, a coral's ability to create healthy tissue is inhibited.
In our reef tanks, corals do not have access to the same variety of natural prey that wild corals do, which is exactly where wild corals acquire vital nutrients, including amino acids. While coral foods can fill some of this void, dosing amino acids can fill in those nutritional gaps in a captive reef resulting in healthier, more vibrant tissue.
Photo Courtesy of World Wide Corals
5. No Pests
Know what to look for when it comes to spotting coral pests. Of course, always dip your corals and be diligent about preventing the introduction of pests but when you can identify the signs of coral pests in your display early, the road to eradication or control is much easier. When pests are allowed to proliferate out of control, the recovery becomes much more difficult and the damage they inflict is more severe.
Be proactive about pests by stocking your tank with natural predators of common coral pests. Certain Wrasses will eat flatworms, Peppermint shrimp prey on Aiptasia, Pipefish can eat red bugs, and the list goes on. If these animals are established early, the chance of experiencing a damaging outbreak of pests is reduced.
Pro Tip: A colorful SPS coral is a healthy SPS coral. When SPS Corals turn brown, it's often an indication of poor health, including irritation from pests.
As we mentioned back on tip #3, flow is incredibly important to the health of your corals. Don't neglect flow and when you think you finally have enough internal flow, you probably could add even more. Just think how much water flow occurs on a natural reef where SPS corals are found. Coral rely upon water flow to deliver their meals, wash away their waste, and uptake various things (elements & nutrients) from the water column.
The tricky part of the flow is knowing when you have enough. There is no golden rule that can help you determine exactly how much GPH of internal flow your tank needs. Most importantly, eliminate the dead spots and don't allow for any one area of the tank to be left stagnant without flow. Eliminating ALL of the dead spots in and around your aquascape requires the right size pumps, placed logically, and tuned correctly which more often than not puts you in the ballpark of achieving the right amount of flow. From there, having adjustable DC powerheads gives you the ability to turn up or turn down the flow as needed to accommodate the needs of your coral.
7. Time vs. Stability
In order to achieve optimal coloration, you need to provide stability over a long period of time. A lapse in stability can start that clock over meaning you can't achieve that coloration improvement without also providing stability. Being that it takes some time for a coral to improve its color, ensuring long-term, uninterrupted stability is key to your success.
8. Fluorescence vs. Color Pigment
The colors among your coral are more than meets the eye. When a coral contains a particular color pigment, you see that color when a matching wavelength of light is reflected off of that color pigment. As long as the light over the coral contains the matching wavelength of light, you will see that color with your eyes. A coral that contains red color pigment appears red only when red wavelengths of light are reflected off that color pigment into your eyes. The same goes for green, blue, etc.
The exact spectrum or combination of light wavelengths over your tank can drastically change the way a coral appears to your eyes, but the actual color pigment does not change. Improving a coral's color pigment takes time and doesn't change immediately based on the color of light you're emitting over the tank. When choosing corals and "designing" the way your tank looks, consider the color pigment and how it will appear in your tank.
Fluorescence occurs when UV-colored light is absorbed by particular fluorescent proteins within the coral. The proteins actually change the wavelength of the light that is then reflected or re-emitted back to your eyes as longer wavelengths (different colored light). A coral that appears fluorescent green under UV light contains fluorescent proteins in addition to color pigment. These fluorescent proteins are common among green, orange, and red-colored corals.
Some corals contain these fluorescent proteins, some do not. Simply cranking up the blue and UV-colored light spectrums will not cause a coral to glow if it doesn't contain fluorescent proteins. When choosing corals, understand they may or may not glow and choose accordingly. Do you want a coral that has rich colors under full spectrum daylight or do you want a solid green coral that glows a brilliant fluorescent green under blue/UV light?