Supplemental Lighting Help

[aarond21]

Looking for suggestions on adding a little more blue to my tank. I have a 90 gal will be mixed reef, but only a few SPS in it. I currently have 2 250w 15" metal halides running 20K bulbs, and I'm just looking for a little more blue in my tank. Not too concerned but upping the PAR with the supplemental lighting but not opposed to it.

Thanks in advance,
Aaron

[mcgyvr]

What bulbs are you using?
Why not just switch to a different bulb?

Here is a quote from user Hahnmeister on another reef forum that we cannot link to for fear of the RC staff taking my first born child or something like that..

How do you define 'bluest'? It is based on perception? Is it based on all wavelengths from 400nm to 460nm (includes actinic), or just blue (450-460nm)? Do you want the bluest bulb regardless of what other spectrums are present... as in, it might have the most blue but not look like it because it also has lots of daylight?

This is the point where perception meets reality. Which wattage you are interested in will also change the responses.

For example: did you know most 20,000K's have less actinic in them than most 10,000Kish bulbs? A 20,000K isnt so much a daylight bulb with more blue as it is a daylight bulb with all the spectrums other than blue taken out. There are many 'daylight' looking bulbs that often have more actnic, and more blue, than a 20,000Kish bulb. Rather than having that 'spike' on the spectral graph that is very narrow in the 440-460nm range, they have less dramatic, yet broader coverage in spectrums from 400-460nm, meaning when you 'measure' the total amount of 'blue' light, they really have more than the one's that 'look' bluer to the eye. 'Blue' looking bulbs aren't so much about having MORE blue than a daylight bulb as they are about just having less red, orange, yellow, green... etc.

Some of your BLUEST bulbs, depending on how you define it:
pheonix 14,000K 250wattDE: .63watts/m2/nm of about 452nm wavelength light. It is really one of the bluest bulbs out there because it has a huge blue spike, yet little of anything else. It really lacks actinic though too, so corals tend to look washed out and chalky under this monochromatic blue light. Its a prime example of a light that makes the tank look cool and blue, yet makes the corals look pale.

Aquaconnect 14,000K 400wattHQI: about a 452nm narrow band spike that reaches about 1.52 watts/m2/nm on Sanjay's charts. The actinic spike at 410nm is only about 0.47 watts/m2/nm. Like many 'blue' bulbs in the 400 watt range though, these bulbs seem more 'daylight' because even though their proportion of other daylight spectrums is so small, our eyes register green and red much better than blue so this bulb actually looks like it has more daylight in proportion to blue than the 250 watt version. Really its just our eyes. A similar comparison would be the pheonix 250... on an e-ballast its pretty much monochromatic blue, but raising up the current to a HQI ballast makes the bulb look more 'white'. Its because while the boost in power raises the spectral curve evenly about .01 watts, this is only a boost in blue of about 3% but results in about a 15% boost in many daylight colors... and since our eyes once again dont favor blue very well, it looks like the relative amount of daylight has increased. Aside from the low actinic output and a good amount of daylight, this bulb is THE BLUEST halide on the market now since it has that one huge spike in the 452nm range. In person, its not the bluest, but it really is. Our eyes also see different colors at different proportions based on intensity (so the lumen/photometric scale is somewhat flawed in this respect). For instance, we see blue better in dim light (since a good deal of our blue color perception is with our rods, normally reserved for dim/night vision) and as it gets more intense, we see less of it. For this reason, less intense lights of the exact same spectrum will look bluer.

G-man 14,500K, BLV/Ushio 14,000K (all same bulb): 0.6watts/m2/nm of 452nm blue... so for a daylight bulb, it has almost the same blue spike as a pheonix at 250 watts. The thing is, this spike isnt alone. This bulb also has a .2-.25 watt/m2/nm spike at 405nm, a .25-.32 w/m2/nm spike at 415nm, a .4 watt spike at 425nm, and a .31 w/m2/nm spike at about 425nm, meaning that even though this bulb looks like a daylight bulb, and it doesnt have the 'blue spike' like at 450-460nm like many 20,000Kish bulbs its volume of blue and actinic trumps that of any other halide on the market. Many 20,000K's have a blue spike and then little else, little actinic even. You just dont see all that blue when the bulb is over a tank because it also has gobs of red, orange, and a green to round it out. Overall, an awesome bulb for output and spectrum though. Makes coral pigments very rich.

Ushio 20,000K 400watt HQI: has a 1.18 w/m2/nm spike at about 458nm but only a .2w/m2/nm peak at about 415nm.

XM 20,000K 400watt M58: has a 455nm blue spike of almost 1.5 w/m2/nm, but only about a 412nm actinic spike of .28 watts/m2/nm. What makes this bulb 'look' bluer to the human eye though is that unlike the Aquaconnect 14,000K it lacks most daylight all together... less than a third of the daylight spectrums compared to the AC 14kK. Its pretty much just blue though, and still keep in mind that if you compare all actinic & blue spectrums (usually done by taking the volume under the line on the spectral graph, or integration of the line in these spectrums), the Ushio/BLV 14,000K has more blue/actinic in its output. That one huge blue spike is all the XM has, where the Ushio has a few nice actinic spikes, extra blue spikes, etc.

[murphreef]

With MH you could supplement with some T5's or an LED fixture.... It will be hard to get a dramatic difference tho as the MH's are so visually bright.

[fishsuse29]

Tagging along. I a currently running 3 250W DE Phoenix 14k with 1 blue + on each side and the color is very nice but I would call it ice white vs blue. There is also very little difference between the T5's being on and off.

Especially if you are used to LEDs which have a much bluer look.

I would be curious to hear peoples experiences on if a Blue+ or Atinic or Led stip will provide more blue when paired with the MH

[aarond21]

Mcgyvr: That is an interesting read. Thank you for posting that. With the bulb now, I'm sure Ill be ridiculed for this but I use Pulsrites, I used them on this same tank for years with my 2x 175w/VHO setup, and I had REALLY great coral growth and color, but I used 14Ks and actnic VHOs. Never messed with any other types of MH bulbs. Any suggestions on a better bulb?

Murphreef: I have debated T5s, also looked at a lot of LEDs too. I really like the Reefbrite and Orphek strips, and just came a crossed the SBAR by SB reef(which I still use the Sboxs). But afraid it'll be drowned out by the MH.

[murphreef]

^ yea that might be the problem.... a simple strip of LED's will be drowned out.

You would be better off with some additional T5's to be honest.... they will be able to give you that "blue" look without being as drowned out like LED's

[fishsuse29]

Originally Posted by murphreef

^ yea that might be the problem.... a simple strip of LED's will be drowned out.

You would be better off with some additional T5's to be honest.... they will be able to give you that "blue" look without being as drowned out like LED's

Just to confirm as I am in a similar boat you think a T5 blue + would provide more blue when paired with MH vs an LED strip/Euroaquatics T5 LED replacement?