In the past, for what it's worth, I've ran a ricordea tank on all blue emitters and had no dino's or otherwise strange outcomes. (Surprisingly!)
Just to imagine out loud a little...
I guess I can imagine if there was a
change in lighting that resulted in a
big change in total flux then I would expect "some" big change in the tank.
Big change = disturbance. And I suppose that makes it something that could hypothetically pave the way for a dino bloom.
As far as I know, dino's bloom when they switch to heterotrophy.
And as far as I know temperature, nutrients and salinity are potential triggers.
It seems reasonable to presume that light
could be a trigger for one or more dino species...but it's not something I've heard of so far.
Do we know if there was an overall increase or decrease in light on either case where dino's bloomed?
Any chance we know the nutrient history of either tank?