Actinic supplementation

[jlinzmaier]

Is actinic supplementation really necessary? I run 400 watt Giesemann Megachromes 14.5K (coral) bulbs and they put out a significant amount of light in the 400-500nm spectrum. What is the benefit of additional actinic supplementation other than creating the dusk/dawn effect with the light cycle. If actinic supplementation is necessary, what is the most appropriate spectrum for tank with mixed corals - 420nm, 460nm, or a combo of both?

I have a 180 gal tank with three 400 watt MH's (Giesemann Megachromes 14.5K bulbs) and two T5 nova extreme 216watt fixtures with a total of four 10K bulbs, two 420nm actinics and two 460nm actinics. Just wondering if my tank would benefit from removing some 10K T5's and replacing them with actinics or if it's simply a mute point since there's enough light coming from the 400 watt halides.

Any bit of info would surely be appreciated

Jeremy

[tpenn187]

i dont think that it is necessary but it is more for the aesthetics of the tank. i know many people who run just mh bulbs and no supplement, i run the supplement because my ushio 14k bulbs are rather white for my likes. if you are satified with the color of your corals the overall look of your tank i would leave it be.

[hyperfocal]

I was running 2x VHO actinic to supplement my Reeflux 12K bulbs, and had with the XM10K and Hamilton 10K bulbs I've run in the past. I just decided to stop, for three main reasons:

1: Heat. Dropping the actinics has shaved a good 3+ degrees (F) off of my daily dawn to dusk temp swings. My temp now varies by about 1 degree over the course of the day.

2: Cost. Running 220W of lighting for 12 hours a day isn't a huge expense, but every bit helps. Plus, $75 a year for the bulbs.

3: Appearance. I like the pop that the actinics give to many corals, but it does come at an expense -- they "flatten out" the three-dimensionality of the tank that's given by the point-source MH lights. They do this by reducing both the sharp shadows cast by my rockwork, and by diminishing ripple lines overall. The 12K Reeflux bulbs give enough blue to bring out the fluorescence of the corals... at least to my eyes.

The only thing I really miss is the dawn/dusk feel the actinics brought by being on before/after the MH bulbs. I'm planning on getting that back with dimmable moonlights.