Led light upgrade

This is all for 12 hour operation. If you exclusively grow autoflowers on an 18/6 schedule, you can adjust proportionally... e.g. you need 2/3rds of the PPFD listed to reach upper thirties DLI. 1.2 x 1.2 = 1.44 m^2 You can use this to determine how much umol/s PAR production you need from a light or array of lights. After that it's assessing efficacy and heat dissapation to determine overall quality of a grow light. To hit ~37ish DLI, you need about 860 PPFD. These may be exact numbers for the example,but you should read it as upper-30s and a rough estimate to get there. My suggestions are based on light produced at the diode and consider normal hanging distances. The actual value at the canopy is probably a bit short of this calculation for a reason... i'm accounting for lost photons - absorbed by walls or lost to radiance. 860 * 1.44 = 1240 umol/s PAR will be sufficient light production for your 1.2 x 1.2 area. A little more or a little less isn't world-ending, either. A little more allows you to mitigate the dimming over time that will happen... by 50k hours with the 'best' lights you'll be at 90% of original intensity (90% of original umol/s PAR production). Heat dissipation is easy to assess.. does the heat sink look flimsy? Efficacy is a bit more difficult. As with umol/s, specification sheets for grow lights are often a bunch of lies or bad math to paint a false picture. You have to compare the light manufacturer's specifications with the bulk of the diodes used -- samsung or bridgelux or osram etc... go to their websites and look how the diodes were tested. if the diodes are not run at the same wattage/amps etc, then it will not last as long nor meet advertised efficacy. Also, you see some list an efficacy higher than what is possible, lol. Nonstop lies... the original diode maker spec sheets has integriry, but the light maker's spec sheets often do not. Basic math can take you a long way.. divide watts by diode count and compare to testing specs. the further off they are, the worse it is and it gets worse at a faster pace the further it is off (an increasing degredation curve, not a straight line). light distirbution -- just about anything will be better than your hps bulb in this respect. Bars / strips of diodes is better than quantum boards, but if the price and specs are right, there are comparisons that could favor a QB in some contexts.