Leonard, I need your help or other VHO experts

[Plato1]

I did a search on this board and RC about the VHO types. I was running 2 aquasuns with 1 super blue (URI). One of my bulbs recently burned out, so I need to reorder soon-as in today. All the threads talked about were 2 and 4 bulb combos.

All I have is softies and LPS. What I was wondering was which has better PAR: 50/50 or super blue? The reason I say this is that I think with two aquasuns the tank might be just a bit pink/yellow. However, I don't like the ultra blue and 50/50 actinic look.

My choices are: run the same combo as before, run 1 aquasun and 2 50/50, or run 1 of each type. So, what would be better PAR-wise between the second two choices? I have a feeling that 1 of each may be too blue, but am unsure about the 2 50/50. If the 50/50 provide a better spectrum or whatever than the super blue I'd rather have them. It was my understanding that the super blues are mainly used for color balance. Is this a correct assumption? By the way, what does PAR stand for? All I can deduce from other threads is it's good for corals apparently.

I'll be holding off my order until I get some sound advice, so thanks in advance!!

Plato

 

[SPC]

Posted by Plato:
What I was wondering was which has better PAR: 50/50 or super blue?

-50/50
Steve

 

[Plato1]

So, I'd be better off going with 2 50/50 and one aquasun than 2 aquasun and 1 super blue PAR wise?

 

[SPC]

That is correct.
Steve

 

[Len]

Two 50/50's with one AquaSun would be produce more PAR then one of each. However, I personally think one of each looks better. Either way, you should do fine with your stock list of softies and LPS.

PAR = Photosynthetically Availalbe Radiation. It's the measure for the quantity of light emitted by a given source between 400-700nm.

Actinics were originally marketed not because of color balance, but because Chorophyll A has the largest absorption peak at 420nm (the spectrum actinic bulbs emit). However, a lot of modern literature cite that PAR is a more important value as zooxanthellae use more then just Chorophyll A for photosynthesis. It's a debatable topic: spectral quality or quantity.

The "problem" with actinics is that the phosphors burn inefficiently compared to others. Therefore, the same energy applied to actinic phosphors will yield less intensity then other phosphors that emit higher spectrums. That's why actinic bulbs produce less energy per watt then an equalavent full spectrum bulb. Although this isn't always the case, it's a useful generalization to think of bulbs in the following way: The more blue the bulb burns, the less efficient (PAR/input energy) it will be.

FWIW, I still use actinics in all my applications because I simply love the aesthetics of actinic bulbs - especially the fluorenscing of corals because of the violet spectrum.

 

[Plato1]

Thanks for the replies! Looks like I'll go with one of each since my impression is that the additional PAR of a 50/50 vs Actinic blue is negligable in my setup.