What grow led lights should i go for ?

FC-3000 from mars if you want to save some on electric costs and get more longevity out of your light. While it costs more, cost of ownership is likely lower than the other options out there. (based on math below, this is a bit overpowered... unless you add co2 above ambient) entry level products that sell for less are simply less efficient and reduced longevity due to driving the diodes harder, i.e. more watts per diode. so, you may need a few more watts for a 80x80 that won't add up to a huge amount due to scale. The yield and quality will be just as good - all other factors the same - like same cct, same spectrum density or whatever it is called lol....simply less efficient / won't last as long is only drawback.. one of which is small relative to scale. Anything 0.375-0.25 watts per diode with mostly samsung lm301 chips will be a bit more expensive. Nothing should drift much further than 0.5watts/diode. this last value is just a ballpark. 0.25watts per diode is roughly where diminishing returns occur.. adding more diodes at same watts doesn't help much at that point. if you look up specs at samsung.com, they are all based on running the chips at 0.25watts. anything above this value reduces longevity and efficacy - in an increasing way as you add more watts. it's also based upon 5000k cct. With this info you can infer whether a light's spec sheet has validity or not. .64 m^2 -- refer to a DLI chart if you want a target of intensity to match environment.. if not adding co2, 800-900PPFD will be up near ceiling for ambient co2. Over 12 hours that is 512 - 576 umol/s. If only running autoflowers, you need less umol/s over 18 hours in a proportional way, which equals about 340 - 380 umol/s out of your light for 18 hours per day. if spec sheet is spot on, this is a great way to pick out a light that fits your area well. how well it spreads it out matters too... at 80x80, a qb (quantum board) is probably going to be nearly as good as a bar-style light... but as you go larger definitely prefer the bar-style as it provides a more even light footprint. If this is a short-term thing.. maybe testing it out a bit... a less expensive light before upgrading isn't a bad idea, but if it is a long-term investment, i'd strongly recommend finding lights at or near 0.25watts per diode and a builk being samsung lm301 diodes -- or else the math doesn't work relative to diodes/watt only from above. all the umol/s and ppfd stuff is good to go regardless.