More enlightened? Or more obsessive? LOL, just my little joke!

So PPFD is better than lumens, no news there. But we don't have PPFD measurements for 99% of the equipment we want to buy. I can't tell someone to go out and get a lamp that gives at least 200 PPFD units (you'll have to assume the right symbols because I don't have them on my keyboard). As sson as your database of PPFD measurements is finished for every lamp in the country, let me know ;)

Given that we generally only have lumens (or possibly just power in watts) for our lights, it is possibly to estimate PPFD based on the spectrum type. Just to get you started, 1000 foot-candles HPS is 110 PPFD units and this is very accurate for any standard HPS. It may interest you to know that essentially all "white" (3000K-6500K) fluorescent and metal halide lighting has PPFD between about 110 and 150 at 1,000fc. It may interest some people further to note that a GroLux fluorescent has PPFD of 291 at 1,000fc. So the GruLux is actually producing higher PPFD (per watt) than any other fluorescent or HID light source, worth thinking about for anyone who thinks PPFD is the only way to go. Lumens are such a poor measure of wavelengths in the violet part of the spectrum near 400nm that rule of thumb conversions for the very blue lights sources used in aquariums are not possible, but then lumens are rarely quote for such light sources anyway, hence the need for individual measurements. PPFD can be calculated very easily for monochromatic light sources, either from watts or lumens.

Unfortunately aquarium people are not concerned with light on the red end of the spectrum so they never bother with HPS lighting
Yes, unfortunate. Add in the fact that they are rarely interested in any bulb more powerful than 400W, usually only 250W, and HPS would likely be a poor choice anyway. But no matter, other reference sources will show you PPFD for HPS lamps if you are really interested. It is in fact astonishingly easy to convert from lumens to PPFD since a standard HPS spectrum is almost exactly the same for all lamps.

Sunmaster doesnt compare so great huh?
There are a couple of things to note here. One is that you appear to have misunderstood the data. Yes, the Sunmaster performs worst on the wrong ballast (lesson for today, do not run a probe start bulb on a pulse start ballast) but is almost identical to the majority of the bulbs on the other ballasts. The second point to note is that the experimental data is flawed in an important way. The method of measuring the flux with the spectroradiometer systematically under-estimates PPFD for light sources with a spiky spectrum, hence the main reason for the apparently radically better XM 10000K bulb. To what extent this may mimic nature is an interesting topic for discussion. My conclusion from the data is that none of these lamps is radically different in PPFD output to any of the others. I would barely know where to start choosing an aquarium bulb, but given this sort of data for a regular plant light, I would make my choice based on other factors such as price, lumen maintenance (PPFD maintenance?), and lifetime.

My final plea for now is that you keep learning about these important concepts, but please please move into the 21st century. Dig a little deeper, look at the tests on the used metal halides, look at the comparisons between magnetic and electronic ballasts, and you will rapidly discover that 99% of all the equipment that has been tested is obsolete and you shouldn't touch it with a barge-pole. Old-style metal halide lamps age so badly that you really need to throw them away after a thousand hours or so. On that basis, any additional cost for pulse start or electronic ballasts is worth it.

Oh and a reminder also: get over the obsession with big CCT numbers unless you are planning to grow coral or shine your light through a foot of water before it hits your plants ;)

There are very different needs for aquariums and for growing plants, needless to say.

Aquariums need not much light of completely different spectrum characteristics 24/7, 365 days in small areas and aesthetic is also important consideration. Temperature control is critical.

Planting requires lots of light of spectrum characteristics depending of objectives and environment: (not talking about clandestine agriculture)
1. Basement seed starting.
2. Greenhouse flowering.
3. Seedling growing.

Most of the time, lighting is needed for a short period of time during the year, and most of the time aesthetics is not a consideration at all.

Also, plants are extremely tolerant of varying lighting conditions.

You really cannot combine the two situations.

dcarch

I agree with shrubs_n_bulbs and dcarch. While it is useful to study the aquarium community, because they are very obsessed and very knowledgeable, you do definitely learn a lot. Unfortunately there are just not too many people participating in this forum and some of the people just seem to be here to sell lamps and spread misinformation. Our local lamp salesman should have banned long time ago.
(New lamps for old! New lamps for old!)

FWIW in my other life, I'm a senior pathologist, who is rather obsessed with perfection himself. In my professional life and in my hobby life, I like to go all the way, understand it all to the maximum that I am able to, and apply my knowledge to the utmost. My most inspiring person is Henry Kuska, who is a member of this forum, and who applies theory, scientific method, painstaking dedication, sweat, and generosity, all tempered with what is practical, and how can resources be applied most efficiently. Henry got me started on indoor gardening, and I have been going strong ever since. I think I started out with germination of rugosa achenes about 6 years ago. For that reason I commend shrub's comments most highly, please take 100% heed of them, because I completely endorse them. My viewpoint is also a very practical one, and although I am blessed that I can afford just about any gizmo or setup my heart would desire, I restrict myself however, I don't just go out and get the "newest and the best", don't play into manufacturer's hype, learn how to recognize real data from bogus. My holy grail is "most bang for the buck". I work hard for my money, and I try to spend it as wisely as I am able.
The aquarium community is very good at evaluating reflectors, that's why I bought myself some lumenmax reflectors, although they're bent metal, the bends to the first approximation if a full parabola. I recommend them.
Choice of lamps: Pulse start metal halide, blows away conventional halide by a country mile, there is absolutely no reason why anyone should use probe start for growing on land. Venture lamps sold by businesslights.com have a perfect spectrum for vegetative, can be run continuously, and in that mode last up to 30,000 hours. For general growing, a ratio of 2 x HPS : 1 x MH maximizes the terrific growing power of the sodium lamp and adds the blue spectrum that is critical for synthesis of chlorophyll and to discourage stem elongation.
Try to design your garden so that it has at least 3 "sides", and cover the sides with mylar. A garden illuminated by 2 lamps, and surrounded by mylar, due to reflection, is equivalent of a garden out in the open illuminated with 3 lamps. For example I built a grow-closet, and lined all 4 sides by mylar, but my next project is to have a garden across the short dimension of a room that has kind of a 8' alcove. The back and sides of the "alcove" are covered in mylar, and the front is open, for general viewing, and access to work on it. Practical things and attention to detail is always critically important.
The aquarium community must grapple with very high scattering losses of water. Scattering is proportional to wavelength (why the sky is blue), and for any useful light to reach the bottom of the aquarium, it must be top heavy with very short wavelength (blue violet). Aquarium owners also grow beautiful ?coral or other vegetation, they have colorful fish, and the extremely high color lamps are essential for the esthetics. Remember, the aquarium owner is buying it for pleasure to look at, we are buying for maximum size of crop for us to eat (vegetables and fruits), admire (various ornamental plant), or smoke, as the case may be. So while I am grateful to the aquarium community, and like yourself have read over extensively the forum discussions, the bottom line is I adapt what I learn there and apply it to land farming. Also why I study the cannabis growing forum, but due to LEO, the best forum overgrow.com was shut down. If you visit plantlightinghydroponics.com you will even notice that under their horticultural lamp selection, they superimpose the photosynthesis activity spectrum with the spectal output of the lamps they sell. However, the regular horizontal 400W pulse start Venture metal halide lamp sold in the sister company businesslights.com has the exact same spectral output as a SunMaster "horticultural vegetative" lamp, but has higher lumen output and longer lumen maintenance.Paul Mozarowski.

Oh, I forgot to mention, due to marketing strategy, the same lamp can be sold for warehouse lighting at one price, and re labelled for "horticultural" and jack up the price x 3, because they think we're stupid. In fact the commercial lamp is actually better because of higher initial lumens, higher maintained lumens. Because the manufacturer does not measure
PAR, or does a b*s "PAR" evaluation that I don't believe, does not means that comparing lumens is bogus. It's the best we have, and when you look at the Photosynthesis Action Spectrum, it's really hard for me to understand why for our pursposes, measurement of lumens is that far off. For example to extremely effective Gavita lamp only has specs for lumens, and it's a hard core horticultural lamp. Note, I am in the doctoring profession, and I have absolutely no ties to lamp manufacturers, I wish I did. I work hard for my money, and I buy the best lamps I can get for the money, but without compromising final results. Why can a Venture pulse start lamp sell for $30, and an inferior Sunmaster probe start "vegetative horticultural" sell for 3x that. And the Venture will outperform the Sunmaster. Answer, because they think we're stupid. The corporation will always maximize the bottom line. They're not in it for public service, they just look at one thing : profit. That is why Jesus Christ said "tear down this temple! and I will rebuild it in 3 day", because the people were being ripped off by a "corporate style" church that was selling the bogus goods, whereas JC sells the real thing for free, which is much better. Same principle applies in gardening.
Paul Mozarowski.

The opening poster might want to consider just buying a few shop lights and growing plants, rather than worrying about qualifying for a doctorate in the physical chemistry of lumenology. :)

Some good points guys. Lots to ponder. Have company for a few days so less time to spend online. Have more response comments and questions than I will be able to put in this post. However, a few things.

As far as my title "Is the aquarium lighting community more enlightened?" goes, that was as much rhetorical as anything else. I was trying to allude to the manner in which the aquarium community as a whole addresses their issues of plan lighting. I was NOT endorsing their lighting as applicable to land plants. The central point of my post was to motivate the gardening community to address OUR type of lighting issues with the objectivity and diligence that the aquarium addresses theirs.

However, I did imply that SOME aquarium lights are as good or better for land gardening as SOME plant lights. We all know perfectly well that there are a lot of bulbs than have cross applications and are even branded with different names to market them to separate crowds. Why is it so blasphemous to say an aquarium bulb could be used on a plant.

I dont have time to say much more, but there are quite a few places where you alluded to places where I could find data "if I want to". I want to, I want to! If you know of a good place to find data PLEASE tell me how I can access it. I love references and URLs. You have provided me with many wonderful numbers and facts but rarely tell me how I can go to the source.

You raise some good points about probe start MH but I think you vilify it more than it deserves. And Shrubs n bulbs, the age of a technology in no way implies whether it is antiquated or not. I have never bothered to replace my CRT monitors. CRT was developed what, in the 30s? gasp the 20th century? The LCDs are nice and light and all that so they do have certain advantages. However, the quality of the screen image on even the best LCD does not match that of standard CRT technology.

When I have more time I want to discuss the bulbs more. I dont think you are looking at the spectral charts and test result numbers for the better performing probe starts from a dispassionate perspective. I am very aware that the probe starts have shorter lives and that is certainly a downside. Im not dismissing the issues you raise, but you havent lead me to much published data to show from where you drawn your inferences.
Shrubs n bulbs; Im not obsessed with color temps. Most time I am just using them for purposes of naming or reference. I look to spectral charts for "color" issues.
Object16, I appreciate your keeping your direct observation of how your plants have performed under such and such light. In the final analysis that is all that really matters isnt it?

Your basic 4000K (or any other K for that matter) Halide lamp generally has a given mix of rare earth elements that give off specific line discharge. The line discharge is exactly the same with either technology. The only difference is in brightness, which is what the plant uses, and that's why we recommend pulse start - more light, more maintained light, longer life = lower price per photon, and less lamp changes = lower operating cost. If you don't mind paying more for the same thing, then by all means. I just happen to like the idea that I can leave a halide lamp on continuous, and it will last for 30,000 hours with an electronic ballast. Buy less lamps = less transport costs, less landfill waste, more money in my pocket, more money to buy other goodies. Also, as gardeners, we have an obligation to the earth to be as efficient on resources as possible. If we can get more lumens per watt, for less cost, then it is our obligation to do so. I like Ushio, they're a smart company:
http://ushio.com/products/generallighting/mh-aqualite.htm
shows an explanation for the aquarium lights they sell
Next link is to their pulse strike page.
http://ushio.com/products/generallighting/mh-pulsestrike-difference.htm
Pulse strike produces up to 105lm/w. Standard halide begins life at 80lm/s and their light output may rapidly decrease over time. Ushio tells us that pulse strike is 40% more efficient over the life of the lamp. If you want to pay 40% more per lumen, then by all means, but I work hard for my money, so I want all the lumens I can get.
I cannot find the Ushio line spectrum, but you can get an idea from the line spectrum on the businesslights.com site, of what to expect with a Venture 400K lamp. Notice the abundant 400-440 peak. You will get the same in the pulse start, just more photons per watt, like 40%more, which is almost like a 400 watt new technology lamp performing like a 600 watt (old technology) lamp.
http://www.businesslights.com/venture-400w-4000k-ed37-horizontal-metal-halide-lamp-case6-p-301.html

I forgot to mention, ur comparison to cathode ray monitors does not pertain to this discussion. Sure cathode ray has nice resolution, but we're not after resolution here, we're after brute force lumen output. Anyway, just because u still use your out of date monitor and like it, I also use an out of date monitor at work, but lcd wins hands down. I have a beautiful 22 " widescreen monitor at home that I wouldn't trade for any crt monitor screen. I am well off enough that I can choose whatever I want to have, but there is no way I would buy a crt monitor. If I was poverty stricken, I might pick one up for 10 bucks, but luckily I have more means than that. Even graphic artists and designers now use lcd monitors. Also the additional drain on the grid, and the power consumption means that we must use the most efficient way of carrying out our lives. pm.