MH Bulbs

[Pillz]

I was looking through sanjays site the other day and noticed That the bulb im using doesnt give out the best par... So im looking to go to a different bulb. I noticed that the geisman 13k has a really good par. Does anyone use them? Or seen one on a tank. whats the color like? I dont have any supplements so its gotta be pretty blue or atleast not yellow.

[wise one]

its kinda white i ran one for a few months but it made the tank look washed out, take a look at the phoenix 14k its got a pretty high par rating its very bright but still has a nice blue tint kinda like a 10k with vho actincs

[xaoss23]

Another thing to consider is that Sanjay did all of his tests in air... putting your bulb over a water surface will dramatically change the results of PAR drop. Ofcourse, how far the bulb is from the surface will make a fairly substancial difference as well.

One thing to consider is what your main interests are. Are you looking for better growth or aesthetics? For maximum PAR, your best bet would be to go with 10K bubls, but many people dont like that much white.

At some point in time, I plan on doing PAR testing on several manufactured bulbs over a system and plot data. I'll also be using several different ballasts (elec vs mag). However... this is a VERY expensive test so its going to take me some time to raise the funds...

[Pillz]

Originally Posted by wise one

its kinda white i ran one for a few months but it made the tank look washed out, take a look at the phoenix 14k its got a pretty high par rating its very bright but still has a nice blue tint kinda like a 10k with vho actincs

Thats actually what Im running right now. I love the blue, But it only puts out like 73 par. My tank is too small width wise for t5 supplements, and I hate how exspencive it is to replace PC bulbs so Im stuck with the whole supplement situation. If I could I was run a 10k with t5 HO supplement.

Another thing to consider is that Sanjay did all of his tests in air... putting your bulb over a water surface will dramatically change the results of PAR drop. Ofcourse, how far the bulb is from the surface will make a fairly substancial difference as well.

One thing to consider is what your main interests are. Are you looking for better growth or aesthetics? For maximum PAR, your best bet would be to go with 10K bubls, but many people dont like that much white.

I want the best of both. I know im going to have to meet somewhere in the middle. But I figure there has to be something that I can use to get really good par and really good color. I cant go any bigger, or I would just get a 400 watt MH. Thats just overkill on a 30 cube. Even a 250 is pushing it IMO. Does anybody have any suggestions that I could do to help?

Also wouldnt par go down if measured in air than in water. I would think that the water would distort the light from penitrating through the surface.

[xaoss23]

youll have a higher DEcrease with water (more matter to penetrate than air)
When Mojo and I did some tests on his tank we got a higher PAR out of the Hamiliton bulbs over the Pheonix. The Pheonix was a better color IMO, but had a loss of aprox 100PAR at 5" below water surface.

BTW, how are you geting your PAR values?

[goodfortune]

Hey Pillz:

I agree; it's hard to strike a balance between bulb color and PAR output. From what I've read the phoenix 14K is one of the best bulbs on the market from an aesthetics and PAR output standpoint.

Other bulbs worth taking a look at are the AB10Ks and the BLVSWs. I have no experience with either, but I heard a lot of good things about the ABs...but they are pricey, and seemingly these days, a bit hard to find.

Also check out this website, which is run by Joe Burger (RC Alias: JBNY):

http://www.cnidarianreef.com/lamps.cfm

It has a good amount of PAR output testing data for various lamps, but not quite as much as Sanjay's site. The website also has some good pictures of what you can expect different bulbs to look like if you ran them.

I'm looking forward to meeting you tomorrow

- Michael

[Pillz]

Honestly I like the look of the 13k better. I really like blue, But I like it when it looks like theres a 10k and actinic at the same time. From the pics at the site you gave me the 13ks gave that look better than everything else.

Do DE bulbs give the same amout of par as SE bulbs?

[goodfortune]

Actually...the ABs (and the BLVSWs I think) are advertised as 10Ks, but really burn at about 13K.

Typically, DE bulbs have higher PAR output than SE bulbs of the same brand, wattage, and advertised color temp, all other factors being equal. However, DE bulbs must be run with a tempered glass shield, which cuts harmful UV but also PAR output. The glass shield must also be kept clean of salt spray and other deposits to reap the benefits that DE lighting can provide.

HTH,
Michael

Originally Posted by Pillz

Honestly I like the look of the 13k better. I really like blue, But I like it when it looks like theres a 10k and actinic at the same time. From the pics at the site you gave me the 13ks gave that look better than everything else.

Do DE bulbs give the same amout of par as SE bulbs?

[mojo]

I'd highly suggest that you get a PAR meter and do your own testing. I found that the Hamilton 14k consistently give higher PAR than the Phoenix 14k bulbs with the same ballasts, fixtures, etc, despite what the reports show.

Also - you quoted the 73 PAR. Do keep in mind that those test are done from 3' or 5' or something, and that you'll be interested in the PAR in your own setup, which is why I'd suggest getting a PAR meter.

You have an Icecap ballast and Phoenix bulb, IIRC. With that exact setup (even the one you have), with the top of the pendant at 10" above the surface, I measured:

@ glass: 1575 PAR
@ 0": 350
5" under water: 225
10" under: 160
20" under: 140

Move the pendant down two inches, and I got:

0": 600
5" under: 300
10" under: 175
20" under: 145

300 PAR will be sufficient to keep any SPS or clam at 5". In fact, according to Dana Riddle, most SPS reach their limit at 300-350 PAR, and start shutting down after that.

If you're really looking for more PAR, then go with a lower color temp bulb (10k or even 6500K). I personally think you've got the best combination for what you want, given the color, tank size, and PAR. If you want a LOT more PAR - go with a 10k XM bulb.

Actually, DE and SE bulbs are physically the same thing, and the bulb itself gives the same PAR. The reflectors for DE bulbs, however, can be more focused on the bulb (because the sheild is moved from the glass envelope around the bulb to the bottom of the fixture). This typically means that you'll get a higher reading, but in a more focused beam. So, given the same test setup with a SE and DE light, a DE light will show more PAR.

[xaoss23]

all above, very good additions.

[bluegrasssweety]

What exactly is PAR? What does it do for your corals? How do you know what PAR readings are good for your tank?

[GeorgeW]

Where might I get a PAR meter? Is this a home depot item or something akin to a computer memory or bus tester (i.e. big $$$ for one person)?

[mojo]

PAR stands for Photosynthetically Active Radiation. It's also seen as PUR, or Photosynthetic Usable Radiation or PPF (Photosynthetic Photon Flux). In any case, it's measured as microEinsteins per square meter per second (mE/m^2/s).

Photosynthesis happens in a range of light from 400 to 700 nanometers, so measuring total output doesn't show us what is actually useful. You could have a really bright blue bulb, but that doesn't necessarily give the corals what they need- the range of light needed for photosynthesis.

Some good articles on PAR:

http://www.advancedaquarist.com/issu...03/feature.htm

http://www.advancedaquarist.com/2006/1/lines

http://www.advancedaquarist.com/sear...chableText=PAR


Most light-loving corals need 300-1000 PAR. Other things, such as ricordia and other softies will prosper at much lower values.


Two companies make consumer-grade PAR meters - LiCor and Apogee. The LiCor setup is about $2,000. The Apogee meter is $199. It's not perfect, but it's what's available and what everybody in the hobby uses. Turns out that the two meters pretty close anyway. What is really nice is that, at least on the Apogee meter, the sensor is submersible, and you can test the actual PAR reading directly where the corals are. I specifically ordered mine with a really long cord to make this possible in any tank.

At $199 for a meter, it's a fairly expensive peice of equipment, but how else do you know if your lighting setup is good enough? When do you know to really replace those bulbs (or could you just lower them down)?

We have talked about buying one as a club meter, but there's a concern that we'll have to worry about someone breaking it, getting lost, etc, and it makes things difficult. A couple of people in the club have one (myself included), and may be willing to bring it over to try something out for you.

[bluegrasssweety]

Thanks Chris
This actually answers alot of MH questions that I had

[RobinsonFam1]

milwaukee has a LUX meter for around $65.00......im thinking of buying it just to see where certain bulb ratings actually stand.....