Advanced LEDs are very good. 2 300w would cover a 3x3 nicely. They cost about $370 on amazon. If you want to go cheaper to start try topledlights.com 300w cost $170. I recomend LST in veg and ScroG in flower when using LEDs.
At what wattage does a 300 run at? It may contain 300 watts worth of diodes, but I can assure you they don't push them that hard. A good light will cover a 3x3 alone if it is actually 300 watts.
Please note that the company who makes these lights is making claims the ones sold on Amazon are knockoffs.
THG , there are a few knockoffs of the Mars2 lights, I hope you get the real one. Best to order through their website. Are you sure PJ is recommending the Mars2 lights, I thought it was just the 3 watt lights?
Fact is, Mars lights, or topled or whoever they want to be called this week are knockoffs of another company out of China. They have apparently made it their mission to market and sell as many of these lights as they possibly can before they start failing. They are a good "starter" light, the end.
Because they are out of China, all they have to do once this starts happening is to close the websites and disappear and no one will have any recourse.
They can be a decent starter light for the average Joe who grows in a tent or smaller closet, but you will never see me even mention their name to someone with a larger style grow room, or professional commercial grower.
Heat is the #1 reason for LED failure, and 5 watt diodes put out way more heat than 3 watt LED's at the same wattage. This is a fact, not an opinion.
I am not sure why you feel the need to quote me, or make comments that include my screen name when talking LED lights. You own one brand of light, grow small time in a tent and know nothing about spectrum's apparently recommending a light to Dr G, telling him it has two switches and then following it by, "But what do I know?" Very little by the looks if it it.
What would the point be of using a light specifically geared towards flowering when he was asking for a veg light? Can you even tell us here at MP what colors are needed in veg specifically? How about ratios, got that information to share as well?
You asked. "but what do I know" well lets see what you know MR1. Enlighten us all here and explain why the light you recommended is a better choice over the light I recommended? We are all ears...
I get a PM on almost a daily basis about recommendations and yes when the topic starts off "but I am on a budget, or the cheapest light I can get that will work" I typically send people in the direction of Mars/topled because they are exactly that. A cheap light that will work. Will you on an average be able to achieve the 1 GPW with a Mars light? No. Are there much better brands that can achieve that number? I average over on the regular and veg a max of 14 to 21 days, so yeah they exist.
When people ask what is the best light out currently, that company never makes the top 10 list. I have said in the past, and now see a few making the same comment good LED's are not cheap, and cheap LED's are not good. The tech is still growing, and until the masses see how well they work GOOD diodes are going to stay expensive, and companies like mars will flourish.
And that my friends is why there is so much negative publicity concerning the tech. There are far too many cheap LED's out and not enough good ones just yet to take the tech to the next level and get pricing down. All about supply and demand, and the average Joe wants cheap.