Actinics: Growth vs Appearance

[acropora1981]

So...this question has probably been asked a million times, but I need to know. Is an actinic (at 420 nm) used for ME? IE, does it just increase my viewing pleasure, or is it the optimal light color for coral growth? I would love to have my tank lit mostly with actinic (2 65 watt PC's, 1 50/50 and 1 actinic instead of 1 10k and 1 actinic) but I want decent growth out of my softies. Anyway...has this debate been settled? Some sources say the light is juts for the viewer, others say that this is the peak photosynthesis range for zooxanthellae....Can someone put this one to bed for me?

 

[nikon187]

well most pure actinic bulbs have very little par. Roughly 1/3 of say a whiter bulb so growth would be much slower.

 

[acropora1981]

But if its at the EXACT peak of photosynthetic power, then does that not compensate for the low par?

 

[jubjub]

for me antinics are purely for aesthetic reasons....besides i think the peak of photosynthesis is around higher nm IE 6500kelvin....

 

[nikon187]

no i don't believe it does compensate. Now if we go to 4 T5 you could easily run 1 fiji purple, 2 actinic+ and a super actinic and have great colour and growth because of the high par of the actinic+/ blue + bulbs.

 

[acropora1981]

cool thanks