Question on actinic lighting

[Kyle46N]

I found these for sale.

http://www.catalinaaquarium.com/product_info.php?cPath=141&products_id=1613

Whats the difference between the 420 actinics 03 and 450 actinics. Visual difference? Does one make green corals pop more than the other? I'm just looking to supplement some 20k halides that are not as blue as I would like. They are more crisp white with slight blue tint. I've done reading on actinics recently but wanted to get your opinion also. Thanks!

Kyle

[Mr Cob]

As I understand it, the higher the number the more UV is in the light. A spectrum above 460 is not tolerable for our corals. Which is why we can't use "Black Lights"...they have too much UV.

The 420nm will probably be perfect for you, I think the 450nm will be a darker blue because of the red uv. I use 450 for actinic suplemant and it works perfect with the 14k MH bulbs I have but I think it is too dark of a blue when the MH's are off.

My understanding of the spectrums could be a bit off, but i think it's pretty close.