I vote...Run your Fuge lights 24/7 and switch to/add LEDs for reduced energy consumption... pH swings...maybe...massive chaeto growth...hell yes. My system ain't perfect...far from it...but I'm nearing $15 a month for selling chaeto to my LFS and about to set up another tank. Thanks to my G/F wanting "Pretty Fishies" that aren't reef safe.
Any suggestions is more than welcome for the 55-gal build. She likes Powder blue tangs, butterfly fish, and other pretty fish that we can find for under $60...
Anyway, I know cameras don't pick up blue light...but I'm just not seeing enough light. Blue is deceiving with PAR though. Any chance you have an LFS or part of a local club that would check out your PAR with you? As much as I love actinics on my corals, I just tried a 50:50 420: 10,000K LED light from ABI and LOVE it over the 12 420-450 LEDs.
THe range of visible colors is much greater and you still get some of the phosphorescence. Something to look into.