Commenting strictly about coloring Acroporas IMO----------
It's always the same mantra..........the nutrient levels are always brought up when a lighting system isn't proving to work well.............It comes off as an excuse.
Or the flat look excuse............not a single person has ever said to me my tank looks flat when they see it in person. There's nothing like MH shimmer...........LEDs alone flicker, I can't stand it, & it looks fake. but with LED and T5 combo it does come close to a MH shimmer look.
The hybrid combo also allows for a brighter tank, not that corals in a cave look........ overly blue and shaded.
I've tracked a lot of successful Acro tanks and they all fall in a ballpark range of---
P04-.02-.10
No3- .25- 5.0 occasionally up to 10.0
The ratio between the two is anywhere from 50-100 to one with NO3 being higher......sometimes up to 200 to one This is very easy to acheive for most reefers. There are some outliers but if you were to draw out a bell curve 90% fall in this range.
I didn't say hybrids are the best. I was responding in general to people who want to use hybrid setups that they work much better when the LEDs are supplemental and on the outsides angled in...........they are just for edge pop and ambient/visual reflective looks.
The spectral distribution of T5s will excite the pigments and get the most out of the corals and they can cover the whole range needed for any acro.
I don't use LEDs to supplement my T5s because I want a good mix of 400-460nm and no one offers this in strip LEDs.......... Most are all blue and narrow, for example, only 450nm.
I'm also convinced the life of the violet LEDs 400-420 suffer shorterm life. The domes blacken over time or they just plain go out. It's why I believe so many LED designs didn't/don't carry enough of them.
Recently, some of the well known brands....Orphek, Radion G4, Reefbreeders, not sure where PAC sun stands, started putting a lot more in their fixtures. They were too light on the 400-420 range(number of diodes in the fixture) for a long time and it's been overdue.
This is one reason why(speaking strictly about spectral differences) there can be a gap in successful coloring of acros.
With diffusers now being used it may only be a short time where coverage is the only issue left to close the gap between bulbs and LED. I'm waiting to see how things prove out though.
If you already have invested in LEDs as the main source, there's no question that T5 will add to making the corals color better and fill in shaded gaps and create a more appealing ambience.
I agree with Doug that there are plenty of stand alone MH setups that don't need supplementation. Sadly the options have dwindled down over the years as many great stand alone bulbs are discontinued.
I don't want to start a debate.......just wanted to clarify my comments and how I see it right now with coloring up acroporas.
