True Actinic T5 Question

[Zach W]

My overarching question is if these Actinic T5 bulbs provide the same "pop" as LEDs in terms of color, and if not why? Everything that I read is telling me that these bulbs increase the fluorescence of corals, but not to the same extent of LED fixtures and I am not sure why this is the case. If these bulbs put out UV and near UV spectrum, why would they not be as effective at displaying the fluorescent colors? Is it just a matter of power output or hotspotting of LEDs or what?

This is not meant to discuss the merits of these bulbs in terms of coral growth and usable PAR vs PUR for these bulbs, just comparing these bulbs in terms of color "pop" compared to LEDs. Thanks!

 

[Ron Reefman]

First, IMHO, true UV and even near UV (violet, 420nm) aren't the best spectrum to get the best fluorescence. I have a true UV 385nm led and it makes for great yellow fluorescence, but not much else. I have a fixture with violet (420nm) and it's only marginally better. I get the best 'pop' or fluorescence with 450nm and 480nm blue leds. These get green yellow, orange and red fluorescence in my tank. This isn't science, it's just my experience.

As for t5 actinic bulbs, you would need to know the spectrum. And unlike leds, I suspect t5s will put out a wider range than the 450 & 480nm leds. I think there are t5 bulbs that can get good fluorescence, but probably not as much as leds.

My tank:

 

[jda]

Yes and No. It depends on the bulb. I depends how many.

UVL Super Actinic VHO used to pop coral like crazy. It was high output and more like the output from a pair of T5s, and people ran more than one of them (so like 4x T5s). They make a T5 version of this bulb, but it works better as a VHO T5, not a HO T5... so you need to drive it with icecap.

I have some actinic T5s over a frag tank and they look nice, make Colorado Sunburst Tips look yellow and generally have nice pop. The two of them get overpowered by the other lights once they come on.

...so to answer your question, I would guess that a good True Actinic like ATI or Giesemann, you would need a few (or more) to see that look during the daytime, but they work pretty well when they are the only bulbs being lit. If you just drop a single bulb in there, then it might be underwhelming similar to just having 4 or 5 RB diodes mixed in with 40-50 whites, reds, greens, etc. The POP from most LEDs is in pure numbers as well as spectrum.

I mix True Actinic T5s with GE 6500k so that I get the nice pop and nice color rendering. I do this over frag tanks and it grows, colors and pops well. If I used 8 bulb, then like 4 of each.

This is off topic, but there are people who have seen what pop the VHO UVL Super Actinics can do and they will never give them up... they are amazing... so you can do this.

Ron -most actinic T5 bulbs still have most of the spectrum, just in smaller numbers... you are right.

 

[Zach W]

I mix True Actinic T5s with GE 6500k so that I get the nice pop and nice color rendering. I do this over frag tanks and it grows, colors and pops well. If I used 8 bulb, then like 4 of each.

the genesis of my question is coming from the fact that I will be upgrading my tank and I am considering a 6 bulb ATI Hybrid powermodule with two LED bars or the 8 bulb version and no extra LEDs. Ideally I wouldn’t run the extra LEDs bars for a cleaner look.

I still want a nice pop for acros that tend to look best under blue LEDs like JF Homewrecker and the like. I’m assuming I can’t make the VHO bulb work in this fixture though. So maybe something like 3B+ 2C+ 2A+ and a 6500? Im new to the T5 world so recommendations are very welcome

 

[jda]

If you like the LED look, then get some XHOs or Orphek bars. Sure thing, right? Just know that you will need more than one of them or they will get overwhelmed too... probably one on each side.

If you want to try the Actinic T5 route, then get 3 of them if you like a lot of that look... I am guessing that it would take about that to have a huge impact when the other bulbs are on. You might need some whiter bulbs to balance out the dimness and windex-y look.

Forget about the VHO if you are buying a sunpower... this is more of a retro deal. If you want to look Big E uses VHO T5s on his tanks and they are amazing.

 

[Zach W]

Thank you!