460 vs. 420 nm question

[zacharytrimble]

What's the difference/advantage of 460nm (bluer looking) vs. 420 (03 "true actinic", purple looking) actinic bulbs...is one better than the other for photosynthesis or for aesthetics...etc?

 

[michaeldaly]

True actinic will cause your corals colours to show up better and flourece (excuse spelling)

 

[The Grim Reefer]

You actually need both to get the best color.