PAR finding from different "250 watt lamp"

[ashish]

Lighting is such a diverse subject and has really no true answers. Everyone has there own opinions but how many of us have really tested different lamps and fixtures? I can tell you I really do not care about all the scientific details regarding lighting and much rather just go based on the most PAR for the lamp.

Currently I am looking for a new 250 HQI bulb replacement for my fixture (120 gallon SPS heavy). Both bulbs will be powered by IceCap electronic ballast. I just want to share with you this article:

http://www.reefkeeping.com/issues/2007-04/jb/

After reading Joe's article I was amazed Just how much of a different these Lamps have.

These are the (average) PAR readings from different lamps(bulbs) (powered by IceCap e-Ballast):

Iwasaki 651
XM10K 530
SUN10K 494
Ushio 414
HM14K 352
Radium 330
CV20K 307
SBURST12K 304
XM20K 270
SUN14K 253
CV15K 242
PFO 13K 227
SUN20K 224
XM15K 187

I have been trying to find the best bulb out there going by people recommendation is :deadhorse1:. We really can't determine what is the best bulb until it's been tested and put to the battle against it's competition (in a controlled environment).

If radium is one of the best bulb (according to a lot), and cost $100 per bulb why is it's PAR so low regardless of ballast? On the other hand the Iwasaki bulb for $80 on marine depot and according to this article has a par 3 times higher then a XM bulb (which is only $10 less).

So based on this finding I am planning on going with the Iwaski 250 watt lamp just for the simple fact - It's par reading is crazy high. Please let me know if I am wrong in my thinking and if you do use Iwaski bulbs please share your experience and growth rate. Thanks

 

[ashish]

Joe concluded:

"I did change my lighting system after doing these tests. After starting the testing, I wanted to find a lamp/ballast combination that put out as much PAR as the Ushio/HQI ballast combination I had been using. Finally, I settled on the combination of the XM10K lamp and the Icecap electronic ballast. The Ushio on an HQI ballast still puts out about 15% more PAR than the XM10K running on an Icecap, but I felt that it was close enough. After making the switch my colors and growth were just about the same as before. The main differences are less heat produced and less electricity consumed. Someone else's goal might be different, but it will make your life much easier if you have an idea of what you are trying to achieve when interpreting the data."

What I concluded (before reading Joe's)

The Iwasaki Par was so high because they used a 6500k bulb. Iwaski does have a 14 K bulb available today and I can only guess what Par ratings it has. I was also shocked with the difference in the XMs 10k PAR (530) vs XM 20k PAR (270) vs XM 15K PAR (187). Without reading this article I would probably go with the 15K bulb but the PAR is lowest of all the bulbs. I think the best bulb for me would probably be the XM 10K bulb - the only problem is I feel they are too white. However, with actinics may look great..

 

[Ron Reefman]

The Iwasaki Par was so high because they used a 6500k bulb. Iwaski does have a 14 K bulb available today and I can only guess what Par ratings it has. I was also shocked with the difference in the XMs 10k PAR (530) vs XM 20k PAR (270) vs XM 15K PAR (187). Without reading this article I would probably go with the 15K bulb but the PAR is lowest of all the bulbs. I think the best bulb for me would probably be the XM 10K bulb - the only problem is I feel they are too white. However, with actinics may look great..

I think you have summed up the issue here. I can't say for sure, but I'd guess that most MH bulb buys aren't based on PAR values as much as they are by how they look to the human eye and hearsay about how well corals grow with any given bulb. Brand loyalty and marketing may also have a lot to due with each persons choice. I ran MH for several years and used a variety of 250W bulb manufacturers (along with t5's and leds). I never saw the PAR list you link to in your post. That would have made a huge difference in my selection of bulbs.

For me the top 3 criteria would have been:
what 'look' do I want (i.e. 10K, 14K, 20K or some mix with t5 or leds added into the mix)
the best PAR value in the color range I want
cost and availibility

My question to you is; given the vast differences in all these bulbs, how well do you think this single ended bulb data transfers over to HQI bulbs? My guess is it could be pretty close to accurate or it could be wildly different. But for me that set of questions has passed as I now run just leds and have my own PAR meter. Good luck.

 

[ashish]

Ron,
The only bulbs I have tried are the 14k and 20k. I really can't stand the 20K because your greens and purples look blue. 14 K bulb was a great bulb (not to blue not to white); but with those PAR reading I am thinking twice.

As far as the HQI to Mogul sockets difference - I am sure there might be a slight difference but studies have shown that HQI have higher out-put (don't quote me on that). Nevertheless you still get a great idea of various lamps/brands/ballast all tested with a PAR Meter. Joe even took pictures of the bulbs and made sure they had been burned in. Even when some bulbs are more used then others, you still get the general correlation of which bulbs perform better under different kelvin ratings.

If you saw this article in your MH days, you would have been even more confused. lol Check out the pictures of the various lamps (with or w/o actinics)!. Its unfortunate that ultimately yellow = high PAR. Even with the Blueline 10 k (very attractive) the PAR is (268); but the Blueline superwhite your at (494).

Everyone speaks regarding the LOOK; shouldn't we be looking at the growth/health of our corals first. Shouldn't we try to get the most out of our Lamps? Actinics should take care of the yellowish look right? I mean may be all these PAR readings are closer then they appear. May be I am just over thinking it. Few weeks ago I was convinced all bulbs where created equally (ballast is important). I wonder how the PAR reading would changes testing a 10k lamp (alone), then test the same 10K PAR after actinics are on(T5, vho, or LEDs). After reading this article I would not be surprised if the Lamps PAR decreased with actinic's on

 

[alton]

Before I get started thanks for posting this, I always like seeing lamp test.
If you are paying $100 for a Radium lamp, find another venue, I am paying less than $80 locally. I would never run a 6500 Kelvin or a 10K lamp, and using only using 3 x 250w Radium lamps in Lumin Bright Pendants to light my 300DD I have 200 to 250 PAR on the sand after 25" of water, and my lamps are averaging 16 months of use before dropping 10%. After two plus years of running Radium lamps with great coral growth and looks I am not going to change. There is more than a lot of PAR to get me to switch lamps, before Radiums I ran Reeflux 12K with good results. Also the position of the lamp can make a difference on which way majority of the light flows, a big issue since the op was not using any reflectance. One thing that could of made this test better would of been to use of real aquarium conditions, a great pendant, and a reading after 24" of saltwater.

 

[sirreal63]

If you really want to spin your head out, try researching PUR instead of PAR. PAR can be misleading because it does not equate directly to photosynthetic needs, PUR does. A lamp can have very high PAR but not in the photosynthetic range, so the light the corals can use is actually less than a bulb with lower PAR but in a better range for PUR.

If you test the 10K with and without actintic supplementation you will find that depending on the source of the supplementation there is very little difference. This can be partly explained by most PAR meters not reading correctly the actintic area. However the PUR will be enhanced by the actintic supplementation. The color of the bulb can also be misleading. A 10k bulb has it's highest peak in the 420nm area and a 20k bulb may have it's highest peak in the 450-460 area with almost nothing in the 420nm area. The 420nm is a secondary peak for photosynthesis and extremely important.

It gets more fun the deeper you dig into it.

 

[ashish]

Alton,
Thanks, when you speak of positioning of the lamps can you be more specific? Do you simple mean have them on a angle? How blue or white was the Reeflux 12k bulb and what made you change to radium?

As far as radium's fixtures go! There's probably no other mh bulb that has proven to grow corals as thick and fast. However, I feel that generally the hobbyist that use radium tend to be more advanced hobbyist who have the best skimmers, best flow, stable alk/cal, Etc. This hobby is really about multiple things working efficiently together for results. With that said I still want to try the Radium bulb but heard they won't work efficiently on E-icecap ballast (may be burn out in 6 months). I was under the impression once I change my 20k to a 15k bulbs I would have more par(but I was wrong). If corals where not sold/ traded at microscopic sizes I wouldn't mind slower growth.

 

[alton]

When scewing in the lamps the inner sleeve position. I believe most lamps for the aquarium trade are universal? I messed up on talking about the position of the lamp, in the industry they make lamps that are BU-Base up, HOR- horizontal, and U-Universal.
I use electronic ballast on mine, the rule is not to overdrive a lamp. After seeing corals/frags grown at a fish store under Radium lamps, when my Reeflux dropped below 10% I made the change.

 

[jaybfresh]

The reeflex m80 ballast is only $80. If you really wanted to try Radiums it might be worth the investment.

Though I've not used one I can say that some of the best local tanks I've seen use radium bulbs. Though like you said, they tend to have the best of everything

 

[ashish]

The reeflex m80 ballast is only $80. If you really wanted to try Radiums it might be worth the investment.

Though I've not used one I can say that some of the best local tanks I've seen use radium bulbs. Though like you said, they tend to have the best of everything

Maybe I will buy 1 ballast and 1 radium bulb for half my tank. My light loving corals are on the right side anyways. Soft corals and LPS are on the left (they grow under the worst MH lamps anyways)

 

[ashish]

If you really want to spin your head out, try researching PUR instead of PAR. PAR can be misleading because it does not equate directly to photosynthetic needs, PUR does. A lamp can have very high PAR but not in the photosynthetic range, so the light the corals can use is actually less than a bulb with lower PAR but in a better range for PUR.

If you test the 10K with and without actintic supplementation you will find that depending on the source of the supplementation there is very little difference. This can be partly explained by most PAR meters not reading correctly the actintic area. However the PUR will be enhanced by the actintic supplementation. The color of the bulb can also be misleading. A 10k bulb has it's highest peak in the 420nm area and a 20k bulb may have it's highest peak in the 450-460 area with almost nothing in the 420nm area. The 420nm is a secondary peak for photosynthesis and extremely important.

It gets more fun the deeper you dig into it.

Thanks,

That's crazy I never knew all that. Anyways, there's really no sense of getting all bent out of shape. My first choice would have been radium but since I am not ready to start changing ballast ill stick with the phoenix 14 k.

I am lucky enough where I am close & gotten in touch with Sanjay for some corals and can go to his house any weekend. However, I really do not want to Add too many acroporas without improving my lighting and flow.. If you look at Sanjays 500 gallon SPS reef,, His lighting consist of 3x400 watt 14k ushio lighting on reflectors (no other supplementation). It's amazing how the man who has tested all the lamps only uses 1200 watts 14k mh on a tank that's 48'' wide tank. He also keeps it very simple and if i where to add any supplementation I much rather try some quality reflectors (only it's hard to find good one's for HQI). Might just start the mogul sockets ones I do the reflectors.