Lights

Mars is 343 umol/s, and the vipar is 270umol/s, if they aren't lying about efficacy. Since one is 100w and one is 150w, it's not just about quality. Technically, the xs1000 is better if it is a true 2.7umol/J light. I cannot find any information on how many diodes there are. This number is acurate only if watts/diodes is near .20-.25w/diode - maybe even .3w/diode if they are best binning chips, but more likely they are not. If it's up around .4-.5w/diode, then it's more likely closer to the 2.3umol/J efficacy of the mars light. So, if you can get this info from vipar, it would help with the decision. So, you want about 900PPFD on 12/12 cycle for photoperiods and 600PPFD for autoflowers on 18/6 cycle These values are always going to be higher than what you can actually get, but that's okay, because 900ppf may be too much anyway.. you may need a bit more. this stuff depends on other local variables. 4ft/10.76 = .37 m^2 340 / .37 = 927 maximum PPFD -- this is enough for both autoflower and photoperiods in a 2x2 tent 270 / .37 = 729 maximum PPFD -- can be used for photperiods, but you'd be leaving some potential yiedl on the table. This is more than enough for autoflowers and may even need a slight dimming. This info is for mature plants. If you plan to exclusively grow autoflowers, either light is fine. I'd go with the xs1000 because you can save a few watts per month and a bit less heat produced from more efficient lights. If you want to grow photos, i'd use the mars ts1000. You'll use more watts, but you'll be able to max out at 50g/sq ft and higher with this light and probably fall short of that with the xs1000 unless you measure from the taint. The wattage differences at 100-150w relative to efficacy is small. 2.3 vs 2.7. The xs1000 is aobut 16% more efficient. it will produce 16% more photons per watt. you might run one light 10watts lower, which amounts to very little over time. .180kw-h/day x 30 is 5.4kw-hours on your electricity bill. 1.00-1.20 dollars more per month when operating full bore? 10dollars/year? you'll probably see more value in maximizing your time and effort per grow with an uptick in yields (photo only) than 10 dollars a year saved. probably not growing full bore 365 days a year, so that's an exagerrated value, too. First few weeks of any cycle are low watt usage and you may take breaks. You can verify all of this with specification sheets on samsung com for the LM301B or LM301H diodes (same exact diode despite different models). I have a sneaking suspicion the EVO chips follow that same line of deception. They are merely the better bin chips at each CCT but run at lower watts/diode, but could be wrong on that, but all the specs look identical except how hard they were run during the testing/measurements... i know for certain about the b vs h part, though. Anyway, anything that deviates from the power they ran the diodes at for the spec sheets on samsung com means it will be less efficient than the spec sheet values. it will also dim faster (longevity.) I saw one of the lights said it can last 100k hours.. that's bullshit. will it turn on after 100k hours, possible, but it'd be a shell of what it once was. If run at spec sheet for any brand/model, you can look up the longevity curve. for samsung lm301, it'll be 50-60k hours before they dim to 90% of original brightness, and it goes quickly downhill from there if you look at the shape of the curve. That's still a long time. the drivers when sold separately only come with a 7 year warranty. heat is the key... if they run hot, they die faster. if you run more watts through the diode, they generate more heat and operate less efficiently than listed.