Using DSLR to determine spectrum of lights on tank

[mvallee_ma]

I just replaced (yesterday) an 8 bulb 60" t5 ATI fixture with 3 Hydra 52's over my 180gallon 6 foot tank.
I am using the wireless AI director which is very cool and tweaked the tank almost to where I like it, I like a natural sun, slightly crispy white 10-12k look.

I have what I thought was a good look but when I took picture with my DSLR the White balance on my camera is being detected at 6750K and looks pretty much like what I see visually. Under the T-5's my white balance did not go high enough on the camera and I ended up having to tweak it after to something like 17000k on the computer to make it look like what I saw.

I am using a new Canon DSLR (5D Mark III) is this an accurate way to determine the spectrum of the lights,

I had the blue channels bumped way up at least 50% higher than the white channel and the reds were only around 10%.
I know time will tell on algae but if at all accurate I am going to guess I will have an algae explosion at that low of a spectrum.
Thoughts?

 

[Auston]

I don't think it would be, they have certain spectrum filters before the lens. You can make a simple spectroscope out of a CD and a ceral box. Look it up on google

 

[Auston]

Hmm but it won't tell you a Kelvin rating....

 

[Reef Frog]

I remember using film DLSRs to measure lighting intensity on grow lights for greenhouse and indoor plant applications. I imagine it could be done with modern digital DLSRs as well.

Readings could be converted into foot candles & lumens, not PAR OR PUR, so it would be of limited use to a SW hobbyist. But it may be useful to verify if a bulb or LED fixture is losing its punch, or compare artificial light to natural light intensity.

I've never heard of measuring spectrum with a DLSR.