Back at it. (and a question)

Hello, I have not been on in a very long time.
I may post updates later, but first off is the major details.
HEAPS of my corals have died. I've been scratching my head wondering why,
I used to do water changes monthly because my tank is quite healthy.
About three weeks ago I broke my right clavicle (collarbone), I couldn't maintain my tank as well as I was hoping to. So yesterday was the first water change in two weeks, and I realised something.... my blue lights from my maxspect razor were not working at all! So my question is:
Do corals depend on blue light?

Tank recap:

Size 65 gallons.
Nitrites are low.
Ammonia 0 ppm ish.
Calcium is 440ppm.
Salinity is about 1.024-5
Temperature is about 28 degrees celsius (82.4 F)

Im just trying to get things under control...
I am now focusing for weekly water changes or if im lucky twice weekly.

I have been backsliding, I almost lost interest in the hobby. (Mountain biking is great...)

Have a great day/night guys, please give me all the tips you can throw at me.

:thumbup: :fish: :fish: :fish:;)