Actinic Lighting

[MizTanks]

Ok, so would it not be wiser of me to install another 18w 10k as far as health and growth of my corals?

[Tom@HaslettMI]

Ok, so would it not be wiser of me to install another 18w 10k as far as health and growth of my corals?

More than likely, yes. But your corals will not maintain their color. You'll end up with a lot of fast growing brown coral.

What type of lights are you currently using?

[MizTanks]

18w 10k flor~18w atenic~x2 moon leds compact~I don't understand???? Corals get their colors from photosynthesis right?

[Sir Patrick]

Yes, corals get their colors from photosynthesis. Different spectrums of light (K ratings) will bring out different colors in your corals, and different spectrums (and intensities) of light for an extended period of time will cause different colors to synthesize in the coral itself.

[Tom@HaslettMI]

Corals get their colors from algae that is living in their tissues. The vivid colors you see in corals is actually the algae producing color pigments to block damaging UV rays. Blue light (not the beer) is closer in spectrum to UV wavelengths and therefore highlights these pigments.

The most important aspect for lighting corals is PAR (Photosynthetically Active Radiation), which is the spectrum of light that is usable for photosynthesis. I believe (but could be wrong) that true actinic bulbs supply little to no PAR. However, in the T5 world of bulbs there are blue bulbs that are not truly actinic which supply good PAR and fluorescence in corals (e.g. ATI Blue+). I'm not sure that such a bulb is available in other bulb types.

For your light set up I'd stick with a 10K and an actinic bulb. That will give you good color and good growth.

[Sir Patrick]

Actinic lighting is beneficial to stimulating zooxanthellae and providing corals with energy. It is also beneficial to have some actinic lighting to replicate the deeper water reef light conditions that ocure naturally on the not so shallow reefs. Actinic lighting isnt a big factor on shalow reef corals, but beneficial to all, especially deeper water corals.

The lower K rated bulbs (like 10k) are, for the most part, the best for growth. Actinics arent necesary, but do play a roll in reefkeeping, and make our corals "pop" and is pleasing to the eye.

But, just a jojo stated, unless you get some heigh quality actinic bulbs with a heigh PAR rating, actinics do very little for growth. They for the most part just help with synthesis and replicate deeper water lighting conditions.