Whitecorals Blog


Five tips for brighter colored SPS corals

1) Check water equivalents regulary and keep them constant 

As simple as it may sound: The basic requirement for well colored corals are the water equivalents. Calcium (420 mg/l), carbonate hardness (7-8 °dKH) and Magnesium (1320 mg/l) should be kept on a normal level. They have no direct influence on the coloration of the coral but water additives, trace elements and other tricks don’t work if these parameters get out of hand. 

However the nutrient values are crucial fort he character of the SPS corals. Here the opinions tend to differ: The „old school“ recommends higher nutrient values, that means about 20-30 mg/l Nitrate and about 0.1-0.5 mg/l Phosphate. With these nutrient values very rich colors can be achieved, but then the colors are very dark and can get dark brown easily, because the density of Zoxanthellae increases. Zoxanthellae are always brown so the higher their density the more the brown algae overlay the actual color of the coral. Nevertheless a SPS aquarium with high nutrient values and beautiful colors is possible.

2) Keep nutrient values low 

The modern reef aquaristic prefers another approach: The nutrient values have to be low, virtually on the detection limit, just like in the ocean. That means you should measure less than 1 mg/l Nitrate and less than 0,05 mg/l Phosphate. It’s important to use trustworthy tests that provide reliable results - so better spend a little more money, it’s worth it. Make sure that the color card of the test is finely graduated and the test is easy to read. Repeated measurements should always deliver the same results. A test result that is not reproducible usually gives false measurements. 

With low nutrient values the coral removes all superfluous symbiotic algae from its cells and so its natural color emerges. With the lower number of symbiotic algae the coral also has more energy for growth. 

3) Provide enough light

Most SPS corals like Acropora, Montipora, Stylophora and Pocillopora are true light junkies, they need an incredible amount of light. Light has a very large influence on the colors of all SPS. Depending on the color, intensity and duration of the light the colors of SPS change massively. If you don’t provide your corals enough light you dpn’t stand a chance of bright colors and fast growth.

Corals perceive light entirely different than humans. We can easily recognize the color of light, but not the intensity. The human eye can adapt perfectly to different brightnesses. If the intensity of a aquarium light is five times higher than the other we only see it as a brighter light but can’t say if it’s 50% or 600% brighter. Therefore subjective assessments of the aquarium lighting are not useful. Here you should rely on proven LED, T5 or HQI lighting. Of course here the elctricity costs come to mind but a tropical reef aquarium can only work when we try to mimic the tropical sun. That must be worth a few kilowatt hours.

Anyone who uses T5 or HQI should exchange the lamps regularly (T5 about 8 months, HQI about 12 months) and not wait until they are busted. Here our eye plays a trick again: After the chance of the lights we only see a slight increase of the brightness and the blue component thank with a strong color growth within about two weeks!

4) Use water additives and trace elements

Some substances such as trace elements, amino acids, vitamins, organic compounds or feed are urgently needed by corals. Always keep in mind that between water volume and coral mass in the ocean is completely different than in aquariums. In the ocean there is virtually an infinite amount of water. This means that substances that are present in the water in the microgram range still never run out, no matter how much the coral consumes. With low water volumes like in the home aquarium it is different, so you have to help out. Moreoever in aquariums not all substances the corals need can be created independently with biological cycles. 

Appropriate water additives can help. Most manufacturers differentiate their water additives in inorganic substances (trace elements), organic compounds (amino acids, vitamins) and feed. Please follow the dosing instructions of the manufacturer. In principle the well-known phrase "more is better" does not apply, however "the dose makes the poison". Overdoses of inorganic compounds may cause problems. Overdoses of organic compounds rarely result in losses since these can be removed relatively easily from the aquarium.

Well-suited care systems use additional small tricks to compensate the imbalance between water and coral volume. So the oversupply of certain substances and trace elements may also be desired and can nevertheless provide a natural environment for corals. 

5) Be patient

It may sound as easy as the above mentioned Calcium and Magnesium values and carbonate hardness, but is often different in reality: Give your corals time! Bright colors don’t evolve over night and also not in a week. As already mentioned the coral cells always have to adapt to external circumstances at first. When a coral cell detects new trace elements or organic compounds in the water it has to reorganize its protein production. Only when appropriate enzymes, channel proteins etc. are present in the cells these new substances in the water can be absorbed and utilized by the cells.

As an orientation for the addition of trace elements usually a delay of 5-10 days is given, after this time you can notice first effects. If the color intensity increases more after this time you can continue with adding trace elements. Once the corals start to get darker you should suspend the addition and then meter the amount you already meterd 5-10 days ago. This is the optimal dosage. For organic compounds it’s a little more complicated since the delay can be bigger depending on the substance. 


Another common phenomenon is that corals take up to 6-8 months to start growing after insertion into the marine water aquarium. The reasons for this are not clear but it shows how long corals need to adapt to changes. Therefore again our advice: Be patient and observe your corals and their changes carefully. The Great Barrier Reef also wasn’t built in a day. 

Comments on this topic

  1. GAST comments


    Also was die Farbigkeit der Korallen angeht ist zunächst ein Faktor wichtig alle Salzmischungen arbeiten der Färbung entgegen da die Zusammensetzung fern der Natur ist und wichtige Hauptbestandteile fehlen und z.t. in falscher Form enthalten sind man beurteilt ein Salz ja nach der schnellen Auflösung.
    Ich selbst stelle mein Salz selber her nach den natürlichen Gegebenheiten im Meer brauch auch kein Balling
    kein Abschäumer kein Filter nur Licht und Strömungspumpe die Korallen haben die natürliche Farbe und behalten diese auch .
    wenn ich so manche Koralle Acropora beim Händler ansehe die so kaum sich öffnet und diese bei mir nach Erwerb einsetzte hat es sich gelohnt jahre lang an diesem Salz zu forschen.
    Salzige Grüsse
    Siegmund Bretzke

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