you can end up with a low CRI light that gives brilliant color rendition in a tank.
but not exactly "natural"....
"candy colored" t5's prove that point I would say..
And consequently a high CRI light can just look mediocre or plain ugly.
Depends on which standard you are using..
Using standard "a" (2856K) yes high CRI will probably be considered ugly.
D50 (5000k-ish) is different as well
Very few high CRI based on d65 (6500k-ish) will look ugly (probably could be more definitive here) and mediocre is a matter of opinion....
Having the full range of color wavelengths at decent quantities almost precludes mediocre or ugly.
Sad part is few diodes of this caliber are available to most and the 6500k diodes put in most commercial fixtures pale in comparison to that quality (conjecture a bit )
ADA is apparently an exception IF that is what they use. Even if lower k bet CRI is high.
Start w/ high color fidelity it is easy to "punch up" any color you want..
Doesn't mean it's perfect nor individually desirable..
Lots of subjectivity ...
Yes overall tone is personal.........................and a personal opinion.
Should one shoot for high d65CRI??.. Personal opinion..
My take on it is you won't make a mistake if you just want a good looking natural tank and pick cyan enhanced, red enhanced high CRI high K whites..
If one had to pick one diode for a tank..I'd pick that one.
Not to argue but to put some personal perspective on it.
Freely admit to not chasing red, just want all colors in fish and plants represented..
That's how I see it, others may differ.. and that is a good thing..