T5s and choosing bulb combos based on PAR - Where to start

Probably the most universal measurements to evaluate when you are considering which T5 bulbs to use on your tank, other than color for your viewing pleasure, is PAR.

The PAR rating is the measured Photsynthetically Available Radiation (all radiation in the visible light spectrum). PAR is often used to measure the effectiveness of bulbs in producing light within the visible light spectrum.

There are quite a few posts on the internet by The Grim Reefer which provide what is accepted as accurate, measurable PAR ratings for the various T5 bulbs which are on the market. These numbers are measured 1" from the bulbs, on a system with no reflectors, to provide you with a baseline that isn't dependent on equipment so you can determine the efficiency of each bulb - you should not use these numbers to discuss/prove/disprove the effectiveness of T5s VS LEDs VS MH

AquaScience:
Special 15K – PAR 320
DUO 15K – PAR 334
22000K Blue – PAR 302

ATI:
Sun Pro = PAR 357
Aquablue = PAR 336
Blue Plus = PAR 311
Actinic = PAR 137
Pro Color = PAR 215

D&D/Giesemann:
Midday = PAR 325
Aquablue = PAR 324
Actinic Plus = PAR 264
Pure Actinic = PAR 157

UVL:
Aqua sun = PAR 345
Actinic White = PAR 293
Super Actinic = PAR 210
75/25 Aquablue = PAR 254

AquaZ:
Sun Pro = PAR 285
Ocean Pro = PAR 323
Blue Pro = PAR 266

Helios:
Daylight = PAR 309
Super Blue = PAR 225
Current Sun Paq:
Daylight 10K = PAR 272
Blue = PAR 252

General Electric:
GE Daylight = PAR 340
GE3000 = PAR 319

Korallen Zucht:
Coral Light = PAR 342
Fiji Purple = PAR 330

Of course, this list isn't complete - and changes all the time as technology does - but its a good place to start

Awesome! So the higher the PAR the better in every case?

Great info!

Originally Posted by b_radusilton

Awesome! So the higher the PAR the better in every case?

That's the typically accepted answer - although, depending on your corals, you could have "too much PAR" - but I am from the school of you can never have too much light

In the end it also comes down to having a nice broad spectrum - if you had 15 fiji purple bulbs whose light spectrum looks like this:

The lower concentrations of light in the 500-600 range 'could' not be providing your corals with all the "light vitamins" they need. (I say could as each coral is different, some might not even need anything for all we know, corals are so alien to us )

If you supplemented your fiji purples with some daylight bulbs, which provide more PAR in the 500-600 range, you can balance out the range of your lighting




I like to think of PAR as a way to compare apples to apples - so when I'm deciding which to buy, I know where I can get the most bang for my buck, and where maybe going with a cheaper bulb will pay off

Great post

That's awesome. I think I finally understand what it all means a little. You don't want just one type, so what covers the middle spectrum? Blues and whites? Or do blues cover about the same as purples?

Originally Posted by b_radusilton

That's awesome. I think I finally understand what it all means a little. You don't want just one type, so what covers the middle spectrum? Blues and whites? Or do blues cover about the same as purples?

the main difference I've seen in the spectrums between the purples and the blue bulbs is the purples have coverage in the 400 and 700+ range, where the blues are mainly 400-500 range

I see. So in the end if you want to cover the whole spectrum you need all three ( blue, actinic, and purple). Would I be able to sustain clams with my t5s?

Originally Posted by b_radusilton

I see. So in the end if you want to cover the whole spectrum you need all three ( blue, actinic, and purple). Would I be able to sustain clams with my t5s?

You can keep clams under T5s anyday of the week, assuming you are using a quality system, with individual reflectors, good bulbs, and good light coverage (you aren't putting your clam in a dark spot)... Caveats would be super deep tanks, and those instances where your tank conditions just don't work for clams

Ohh, and as far as 'light vitamins' go, actinics provide very little, they are really just for your enjoyment.... So, if you think you are limited with bulbs, just use more blue bulbs, instead of actinics so you still get the growing power you need

Thanks so much. I have a 6 bulb system and a 75 gal tank. This has been so helpful!

Great write up Joanne! As Joanne mentioned, the PAR numbers, in the first post, are measured without reflectors. One of the key "secrets of success" of T5HO lighting, is the ICR or Individually Contoured Reflectors. These reflectors force much more of the available light, thus available PAR, back into the water. Whenever considering T5HO lighting, keep this in mind, as there are a lot of cheap fixtures available, most on Ebay, that have a single "parabolic" reflector, instead of ICR. ALWAYS use ICR with T5HO lighting.

ALSO, make sure that any fixture, you're considering, has Advanced Electronic Ballasts. These are the best ballasts for T5HO lighting, powering the bulbs to the correct wattage AND allowing bulbs to remain lit, even if 1 bulb burns out.

One more thing to consider...

T5HO lighting produces PAR based on the heat of the bulb. If the bulb is too hot, PAR is reduced. The cooler the bulb, the more PAR produced. Thus, you can produce more PAR, from your T5HO lighting, by actively cooling the bulbs, with fans.

Joanne, I have been kind of set on LED's since I saw them, and saw that their light has a shimmer to it, similar to metal halides. I definately dont want metal halides due to heat and wattage, I do want the highest par per watt I can get. Should I be looking at t5's also or maybe a combo of t5's and LED's? I am just begining my lighting fixture research and could use some input. Im open minded here, and dont really have a formed opinion, other than I dont want the wattage of a small space heater hanging over my tank and running 1/2 of the day.

Originally Posted by Variko

Joanne, I have been kind of set on LED's since I saw them, and saw that their light has a shimmer to it, similar to metal halides. I definately dont want metal halides due to heat and wattage, I do want the highest par per watt I can get. Should I be looking at t5's also or maybe a combo of t5's and LED's? I am just begining my lighting fixture research and could use some input. Im open minded here, and dont really have a formed opinion, other than I dont want the wattage of a small space heater hanging over my tank and running 1/2 of the day.

Just my .02 - but from the limited experience I have had with LEDs, they work well, and the colors are amazing, but, the light spread is limited, and you need a lot of LEDs to get that edge to edge lighting you'd like on a tank.

I would put them on the same level (assuming both were designed to provide the same PAR) - lighting efficiency wise. And for now, a DIY T5 kit is still cheaper than a DIY LED kit, especially on a 120 gallon tank.....

Looks like I need to look into some t5's. I wonder if I add a few leds, I can get the shimmer effect.

Originally Posted by Variko

Looks like I need to look into some t5's. I wonder if I add a few leds, I can get the shimmer effect.

that is what quite a few people do - the ecoxotic stunner strips are nice, put a strip of them across the front of your tank and call it good Stunner LED Strips - Aquarium LED Lights

Great post Joanne!!

I run t5's over my tank, and i have to wait to get my shimmer fix when the moonlights come on (6 leds)

btw nice post Joanne!