The magic answer is ..."it doesn't matter...."
In all seriousness, when you turn on the whites, the blues are one as well... and when you choose the actinic mode, only the blues stay one. That being said, you want to use the whites for a broader spectrum. And, if you use the stock Fluval light with a timer, the light remembers it's last state of "On" or "Off" but when turning on, it defaults to the white / full spectrum setting.
The light itself does well for soft corals / LPS. I found SPS to be possible but a bit challenging as the highest concentration of lights / PAR is within a narrow band directly under the light bar.
After about a year, I've since upgraded my light to an Aqamai LRM for greater control and more versatility in terms of range of things I can keep. But, I did reuse the stock light to my Fluval Edge for use to grow out BTAs and other frags and find it to perform well there.
One pro-tip for you... If you look at the LED side of the light that is directly below where the switch is, there is a chip the sometimes have a leg exposed (the rest of the light is well sealed in a silicon coating of sorts)...if you see the led as such, I suggest sealing it with some silicon as well. Over time, the leg tends to corrode from the saltwater splashing on it...at least it did on mine. When Hagen \ Fluval sent me a replacement under warranty, i noticed the same situation.
Hope this helps...
