Key takeaways
- The Philips Master GreenPower 1000W DE HPS delivered the highest total PAR in our 3' x 3' test: 18,852.
- Philips, Gavita Pro Plus, Ushio Pro-Plus and Genesis finished within about 1.5% of each other, so any of the four is a strong output choice.
- Best to worst was about 7.4% in total PAR, which is enough to matter across a commercial flower room.
- The spectra of all the lamps overlapped closely; the separation came from total output, not color.
- Plan to replace a DE HPS lamp at or before its rated life, which is 10,000 hours for both the Philips and Ushio lamps we carry.
Hey everyone, Nate from Growers House here. Today we’re running our next comparison: the best double-ended 1000W HPS lamp test. We’re doing this because Hortilux recently came to market with a new 1000W DE HPS lamp, and we wanted to see how it stacks up against the most popular players in the industry.
So we pulled together nine different 1000W DE HPS bulbs and tested them under the same equipment to keep it fair. Let’s look at the spectrum, then jump into the intensity data (PAR/PPFD) so you can see which 1000W DE lamps actually delivered the most usable light.
This test was run in 2016, when Hortilux's first DE lamp came to market. The measurements have not changed, but the market has: seven of the nine lamps are now discontinued, and the section on conclusions lists the double-ended HPS lamps available today.
Spectra of the Best 1000W DE Lamps
Here are the spectrum results for the best 1000W DE lamp test. When you compare the spectra of these different grow bulbs, you’ll notice they overlap extremely well. The differences are mostly minor intensity changes at specific wavelengths, not major shifts in the overall spectral shape.
That makes sense because most HPS lamps share a similar chemical makeup (sodium plus trace elements). So no surprise here—the spectrum isn’t where the big separation happens. The real story is in total output across the canopy.
How We Tested: PAR/PPFD Mapping Over a 3’ x 3’ Footprint
Here’s the test setup. We placed each lamp over the same 3 ft x 3 ft footprint, because we wanted enough measurement points to get a statistically meaningful picture of the photosynthetically active radiation (PAR) each bulb produces. PAR is the intensity from 400 to 700 nm, which is the range plants use most effectively for photosynthesis.
Every lamp ran on the same ballast and reflector, so the lamp was the only thing that changed. We took readings across the full 3’ x 3’ area and then used that grid to calculate totals and comparisons. If you’re doing your own checks at home or in a commercial grow room, a reliable Light Meter (PAR meter) makes it much easier to validate what your lighting is actually delivering at canopy level.
Best Metric to Compare Lamps: “Sum of All PAR Over 3’ x 3’”
When you’re trying to figure out which lamp truly did best, the number we focused on most was the “Sum of all PAR over the 3’ x 3’ footprint”. That’s simply taking every measured point in the grid and adding them together. The bulb with the highest total delivered the most overall usable light in this setup.
In this test, the best-performing 1000W DE lamp was the Philips Green Power 1000W DE HPS. (Its current version, the Philips HORTI MASTER GreenPower Xtra, is in the table of lamps we carry in the conclusions.)
Our hypothesis going in was that Philips would probably do best. We’ve heard similar results from other lighting manufacturers running higher-end testing (like goniophotometers), and there’s been a lot of talk about Philips’ ignition technology being a real advantage in 1000W DE HID performance.
Results: Top Performers Were Extremely Close
We recorded a total PAR sum of 18,852 for the top performer. What’s interesting is how tight the top group was. Four lamps performed very well, and they were all within about 1.5% of each other—so we’re not talking about drastic differences up top. I’d consider all four of these bulbs strong choices if output is your priority.
| Top Tier 1000W DE HPS Lamps | How They Landed in This Test |
|---|---|
| Philips Green Power / Green Master Power 1000W DE HPS | Highest total PAR sum over 3’ x 3’ (recorded total: 18,852). |
| Gavita Pro Plus 1000W DE HPS | Top-tier output, within ~1.5% of the leader. (Discontinued.) |
| Ushio DE Enhanced Performance Pro-Plus 1000W | Top-tier output, within ~1.5% of the leader. (Find Ushio DE Pro-Plus options) |
| Genesis 1000W DE HPS | Also in the top group, very close to the leader. (Discontinued.) |
Full results for all nine lamps
The same numbers as the data table above, in text you can sort through on a phone. Total PAR is the sum of every reading across the 3' x 3' grid, and the gap column shows how far each lamp finished behind the leader.
| Lamp | Total PAR | Behind leader | Average PPFD | Min / max PPFD | 2016 MSRP |
|---|---|---|---|---|---|
| Philips Master GreenPower | 18,852 | — | 754.1 | 411 / 1,136 | $157.99 |
| Gavita Pro Plus (discontinued) | 18,702 | 0.8% | 748.1 | 402 / 1,113 | $147.95 |
| Ushio HiLux Pro-Plus | 18,668 | 1.0% | 746.7 | 396 / 1,127 | $169.95 |
| Genesis DE (discontinued) | 18,577 | 1.5% | 743.1 | 383 / 1,122 | $119.00 |
| Nanolux MaxPar (discontinued) | 18,251 | 3.2% | 730.0 | 367 / 1,106 | $109.99 |
| Ultra Sun DE (discontinued) | 18,183 | 3.5% | 727.3 | 336 / 1,086 | $119.95 |
| Solistek (discontinued) | 17,836 | 5.4% | 713.4 | 364 / 1,093 | $159.99 |
| Hortilux DE (discontinued) | 17,804 | 5.6% | 712.2 | 372 / 1,070 | $149.95 |
| Prism Lighting Science (PLS) (discontinued) | 17,465 | 7.4% | 698.6 | 296 / 1,053 | $79.99 |
Outside the Top Four: Value Pick and a Notable Miss
Now, jumping into the lamps that didn’t land in the top four: one we were really hoping would be up there was the new Hortilux 1000W DE lamp. In this first DE iteration, it didn’t quite make the top tier. (That Hortilux DE lamp is discontinued.)
If you’re looking at output vs. budget, the Nanolux MaxPar DE HPS 1000W stood out as a strong “bang for your buck” option. It came in just behind the first four, while costing about two-thirds the price of most lamps on the chart. (The Nanolux MaxPar is discontinued.)
Double-ended vs. single-ended HPS bulbs
Every lamp in this test is double-ended: the arc tube is held at both ends and connects at each end, instead of screwing into a single mogul socket like a standard single-ended bulb. That means a DE lamp is not a drop-in swap for a single-ended bulb. It needs a double-ended fixture, with a reflector and an electronic ballast built for it; the Philips datasheet, for example, lists a 400 V lamp supply and an electronic system.
If you run single-ended 1000W HPS, our separate 1000W single-ended HPS bulb test ranks those lamps the same way. We also put standard and double-ended bulbs side by side in the standard HPS vs. double-ended test.
Conclusions: Why a 7.4% Output Gap Matters in Hydroponics
One more note that really matters for hydroponic growers: the difference between the best lamp and the worst lamp in this test was about 7.4%. That’s big enough to be meaningful in crop yield—especially in commercial runs where small percentage gains add up fast.
So, final thoughts: based on this 1000W DE HPS comparison, differences in lamp quality aren’t just marketing. There are real performance differences in double-ended HPS bulb output. Think about your priorities—maximum output vs. budget—but if you’re growing high-value crops and want the most overall light on your canopy, the Philips 1000W DE delivered the highest total PAR in our setup.
The video below was recorded for this 2016 test. Of the lamps named in it, we still carry the Philips, now sold as the GreenPower Xtra, and the Ushio Pro-Plus; the Gavita DE, Genesis, Hortilux DE and Nanolux MaxPar lamps are discontinued, and the lamps we carry today are in the table below.
Video transcript about 6 minutes
0:10Hey everyone, Nate from GrowersHouse here, and today we are doing the next comparison, which is our double-ended thousand HPS test. And we're doing that today because Hortilux just came to market with their new DE thousand-watt, and we really wanted to see how it stacks up against the big players in the industry. So we brought out eight different DE HPS thousand-watt bulbs, the most popular ones in the industry, and we're gonna see how they do against each other. So let's check out your intensity spectrum and run some analysis on them. Let's jump into it.
0:53OK, so here are the test results. So looking at the spectra of these different light bulbs, you'll notice that they all marry each other extremely well. The only time you can actually notice that there's any difference in, you know, the spectra of these light bulbs is really, you know, minor differences in intensity between them at different wavelengths. But they all have the same, really, chemical makeup, so we expected the spectra of all these to really look very similar to one another. So no surprise here, so let's move on.
1:28Now you can see, you know, how we did our testing. We essentially put the light above our three-by-three footprint, and we went out to three by three just because we wanted enough points to get a statistically significant, you know, total sum of PAR, which PAR is effectively the photosynthetically active radiation that the light bulb's giving off. So that's, you know, the spectrum and the intensity between 400 to 700 nanometers, which is the width of the wavelength that plants use best to photosynthesize. So in taking the sum of the intensities in all these points within a three-by-three area, we were able to glean quite a bit of statistical data. So let me pull it up right now.
2:09So here's a chart that shows off, you know, what we think is probably the best number to focus on to figure out what lamp really did best in this test, which is the total PAR, which means taking every point that we measured and adding them all up. So when we did that, the light that turned out to give us the most amount of light, using the same ballast and reflector, was the Philips Green Power. And honestly, our hypothesis was that this lamp would probably do best, because we heard from other lighting manufacturers who have done similar testing, or even testing using equipment that's far superior to ours, including like goniophotometers and, you know, 50 to 200-thousand-dollar lighting instruments and things of that sort. They were saying that, you know, Philips, with some of the patented technology they have, is really producing just about the best DE lamp out there.
3:11So we recorded the total PAR of 18,852 when we summed them up. But that said, there are four lights that we felt performed pretty well. I mean, that was the Philips Green Master Power being number one, and then it looks like the Gavita Pro Plus and the Ushio, and then the Genesis. And all four of those lights, actually, if you add up the sum of their PAR, they're within about 1.5 percent of each other, so we're not talking about drastic differences. I would consider all those bulbs very good. If you want the best bulb out there as far as technology, probably the Philips, but it seems like the bulbs that are also, I know the Gavita and the Ushio, are made for sure by [inaudible], that's a German company that makes a lot of really high-end double-ended lamps for quite a few companies, and I know that their lamps turned out to be some of the best ones out there. I'm not sure where the Genesis is made, but it's very possible it's also made by the same factory, with maybe some minor tweaks.
4:15So that said, jumping into the lights that were not in the top four. I mean, one of the ones that we were hoping was going to be up there, the Hortilux, didn't quite make it with their first DE iteration. And then, looking into maybe what the most bang for your buck is, because I know a lot of our customers are interested in that, the Nanolux MaxPar lamp did pretty well. I believe it came just behind those first four, and it is coming in at a cost of about two-thirds the price of most of the lamps on here, most of the ones that scored in the top four. So that's definitely what we call our price performer.
4:53And then, you know, that variance between all of these, when we added the sum between the best lamp and the worst lamp, was about 7.36 percent. So I would say that's definitely, you know, you can see the difference. 7.36 percent in your crop can be a huge difference, especially if you're on a commercial scale; that can be, you know, definitely multiple thousands of dollars. But, you know, we're not talking about differences in the ten to twenty percent here.
5:24So that said, I mean, this is some very interesting information, and doing this test, you know, it got us thinking about how lamps test if you test multiple of the same lamp. So we started doing that testing right now. We're going to put out another test: we're gonna take, like, the Philips Green Power, maybe a few other lamps, and test, like, six of the same lamp and see what kind of tests we get, to see kind of what variance you have from bulb to bulb, so that we know whether, you know, these percentages are extremely significant or not, or whether it could be just a little bit of chance that gives you a couple percent swing, or maybe it's just a fraction of a percent swing.
6:05Other than that, this is Nate from GrowersHouse. Thank you very much for visiting our test. If you have any questions or comments, please give us a call or email. Have a great one. Happy growing!
Double-ended HPS lamps we carry today
Two of the lamps from this test are still available: the Philips, in its current GreenPower Xtra version, and the Ushio Pro-Plus. The others below were not part of the 2016 test, so their numbers are the manufacturers' ratings, not our measurements.
| Lamp | In our 2016 test | Rated PPF | Color temp | Rated life and output |
|---|---|---|---|---|
| Philips HORTI MASTER GreenPower Xtra 1000W DE | Yes (earlier version, 1st place) | 2,150 µmol/s (datasheet) | 2000K | 10,000 h to 10% failures; 95% photon output at 10,000 h |
| Ushio Pro-Plus 1000W DE | Yes (3rd place) | 2,100 µmol/s | 2100K | 10,000 h rated life |
| MegaPhoton 1000W DE Lamp Pro | No | 2,100 µmol/s | ~2100K | ≥95% lumen maintenance at 10,000 h |
| Iluminar IL DE HPS 1000W | No | Up to 2,050 µmol/s | 2000K | Over 95% PAR retention at 10,000 h |
| Growlite Real Red 1000W DE | No | About 2,000 µmol/s | 2000K | 20,000 h rated life |
| Interlux 1000W HPS DE | No | Not listed | ~2100K | Not listed |
| Matrix 1000W DE HPS | No | Not listed | 2100K | Not listed |
Complete systems are also available if you are building a room from scratch, such as the Iluminar IL DE full fixture, which includes the HPS lamp.
When to replace a double-ended HPS lamp
Ushio's datasheet recommends replacing the Pro-Plus at or before the end of its 10,000-hour rated life, and recommends relamping a whole room at once rather than one fixture at a time. Philips rates the GreenPower Xtra at 95% of its original photon output at 10,000 hours. At 12 hours a day in flower, 10,000 hours is a little over two years of continuous cycles. Swapping every lamp in a room together keeps the canopy even, instead of leaving one fixture a season behind its neighbors.
Many rooms are also moving from HPS to LED. If you are weighing that change, our guide to how many LED grow lights you need works out the wattage and PPFD for a given canopy, and the LED grow lights collection lists every fixture's draw and efficacy.
If you have any questions or comments, please give us a call or email.
Happy growing,
Nate