1000W Hortilux HPS Bulb Spectrum & Intensity as Wattage Changes

View the Spectral Chart Infographic PDF




Hi everyone, Nate from GrowersHouse here. Today were going to be doing was brought up by one of customers as a really good question. This customer normally uses a 1000W ballasts, but he wanted to see what happens to the bulbs spectrum and intensity as he dials this ballast down from the SuperLumens feature, 1000w, 600w and down to even 400watts. In particular he was using a Solis Tek ballast and a 1000w HPS bulb from Hortilux so we thought, why not throw these guys under our spectrometer and see how the spectrum changes as a 1000 watt bulb is ran at different wattages not only that but how does the overall intensity change and are there any deficiencies or inefficiencies that are gained by running a 1000w bulb at 600watts. And is the intensity linear or maybe exponential in how it decreases.




We will be using our new spectroradiometer, The Black Comet from Stellar Net which we are now using to do all of our spectral readings and par readings. Rather than using our handheld par meter we used before. Which is great par meter for standard uses, but we found that the meter we were using is not optimal for producing the kind of data and specific accuracy we wanted for our tests. (the hand held we used had a plus or minus 5% on readings depending on the type of lighting you were using led, hps, hid MH, CFLS) with this new very sophisticated Black Comet spectrometer we are able to take accurate measurements and calibrate each time we take a light measurement to get the most accurate light reads possible. This is university research grade equipment and we are really excited to be using it and get some really useful data out of it. So let's take a look at our results.




So using the Solis Tek Matrix 1000W Dimmable Ballast with a Hortilux Super HPS Enhanced 1000W bulb with a Growlite Karma 8 inch Air Cooled Reflector which has panels that cover the air cooled ducting and we thought it would put a nice even footprint over the space let's see we tested this bulb in every wattage setting in the Solis Tek Matrix it has 6 total wattage settings, it has 1000, 600 and 400 watt setting and then it has a Super Lumen setting for each one of those settings, bring them up to 1040, 630, 420 respectively. We also measured the voltage and we tested this at 120 volt the wattage at the wall for each setting and the amperage, all at 60 hertz, and we came up with a ratio of PAR/ watts this center par reading is really right below the fixture at approx. 24inchs above the light meter we measured the light intensity in micromoles. and we came up with the par / watt ratio so you can see how much usable photosynthetic light you are getting per watt of input, there is a pretty good correlation between when the ballast is operating at higher wattage its actually more efficient at putting out usable light for your plants. As you dial your 1000w bulb to 600 and 400 watts you'll actually be losing some efficiency you'll also be losing some wattage. We thought that was a good way to see the efficiency of the lamp.




If you zoom into the spectral chart you can see the differences in the spectra from each wattage setting. You can see the differences for each settings compared to its super lumen setting. What we thought one of the most interesting things was how the graph actually changes as you go from 1000w to 600, you'll notice the lamp does not cover as wide of a spectrum when you change down the setting from 100w to 600w and even from 600 down to 400. S so what you're getting is really a narrower spectrum as you're dialing your ballast down to lower wattages. You can see at the 1000w you're getting much more broad coverage which you would think is more beneficial to plants with more photosynthetic capability.




Lastly we made a graph showing just the three 100, 600 400 settings so you can more easily see how their curves change and also one for just the super lumen settings.




We had a lot of fun doing this test, it taught us a lot about how these bulbs output can change with changing the ballast.




If you have any other tests you'd like to see put it in the comments here or email us or call us- This is Nate from GrowersHouse, Happy Growing!