Coloration of SPS Corals

Everyone knows that the type and wattage of lights has a lot to do with the health and coloration of corals. That also means that placement of corals in the tank will have an affect as well. After all, the closer the coral is to the top of the tank the more light it receives.

One of the requirements of SPS coral is that it receive intense light. And watts per gallon is a measurement typically used in the reefing hobby. But, that is a deceptive ratio because the height of the tank plays an important part. A lot less light will reach the bottom of a 36″ tank than a 12″ frag tank.

Courtesy of: www.oracorals.com

PAR value is another way of determining how much light reaches a certain point.  In strictest terms PAR stands for Photosyntheic Available Radiation.  PAR is typically reported in microEinstein/second/m².   Its less important to know the equation, but important to understand the relative PAR value at each level in your tank.

So, after using a par meter on my tank I realized that the PAR readings drop off significantly from the surface to the sand bed.  For reference, I have a Current Outer Orbit Pro on my tank with 3×250w 14K Phoenix metal halides and 8×39w UVL Actinic bulbs.  Its about 1062 watts of light.  My tank is 24″ deep and 125 gallons.  Using the watts/gallon ratio I get about 8.5 watts per gallon.  But, the par value just under the surface of the water was close to 1000 and at the sandbed was closer to 250.  A significant drop off.

So, I decided to see what the effects would be of placing a similar SPS coral in three different locations.  For my test, I used the ORA Red Planet Acro.  This coral is beautiful.

To the right is ORA’s Red Planet.  Notice the almost hot pink tips and polyps and the green base?  Beautiful.  But, what effect does placement have on the coloration?

The image below shows the location of 3 ORA Red Planet Corals in my tank:

Now, bear in mind that Coral #1 has been in the tank for about 6 months longer than the other two, so its size is different.  But, this is not about growth, its about coloration.

Here are the three corals in order form top to bottom.

1.  Highest in Tank

2. Mid-Level in Tank

3.  Lowest in Tank

Notice the coloration difference?  All three corals are healthy!  But, the intended color of the coral (in my opinion) is more along the lines of 2 or 3 which are progressively lower in the tank.  So far, I like the coloration of number 3 (the lowest) the best.

Remember this when you add your next coral to the tank!

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