SPS Question?

[North Bay 101]

Greetings,
I have 9 SPS frags. 2 Montipora Digitata, 1 Acropora Millipora and several others unidentified. My question is this, the polyps are out all the time. Is this normal? The nice purple Montipora that I bought last week is now colored brown from the polyps. All of the SPS are growing like crazy and the lighting is a single 400 watt Iwasaki 6500k bulb above a 46 bow. I want more color in the tank and thought the right way was to add colored frags. Thanks

 

[KenH]

Monitopora Digitata have their polyps out during the day which sets the primary color of the coral. There are versions that have very nicely colored polyps such as orange which will add quite a bit of color to a tank. Most other coral polyps do not hide the color of the coral when they are extended, so that shouldn't be much of an issue for you.

SPS coloration in general is somewhat dependent up alkalinity levels and lighting intensity/color temperature. It is entirely possible to buy a purple coral and have it turn brown if these conditions are not adequate. You might make sure your alkalinity level is at least up around 3.5meq/l or so to ensure best color. And although some will argue the point, many people find that SPS corals tend to color up better under higher kelvin lighting than your current Iwasaki.

--- Ken