Ideal tent size for 900w led

[billygoat]

do some research and figure it out, homeboy.

You need to chill out bro !

[Naked Monk]

As mentioned LED lights are a tough market to follow with all the crap out there, but bottom line is they are 90% all made in China. Difference being that the US, Canada and European markets will advertise true watts being they take in consideration that an LED diode is NEVER ran at 100% as it will shorten the life of the diode and put stress on the PCB. Usually the diode is backed off to about 70%-80% with resistors. Meaning a 3w Diode will actually draw 2.1 watt to 2.4 watt and same respectfully for a 5 watt diode. The Chinese on the other hand will tell you its a 900 watt fixture when its actually only 720 watt, they take 3w x 300 diodes and call that a 900 watt light, not taking in the consideration that they diodes have been backed off.  And as far as your coverage of the LED, you can pretty much be safe is you have a 150mm wider foot print that the fixture itself. So say for example your light is 600mm wide and 600mm length, then factor your foot print to be about 750mm x 750mm, this of course depends on the lens used on the LED diodes. Then there is the 3 watt diode units, and the 5 watt diode units (this is guessing your unit is fitted with SMD diodes and is not a COB LED light, which is new tech again and a different story), but the 3 watt diode units are sufficient for small canopies like small plants, SoG, or ScroG as you don't need the penetration that the 5 watts provide and the 5 watt diode units are good for deep thick canopies, like thick bushy indicas, grown as a tree/shrub style grow as they provide that extra penetration into the plant density. Another thing that people seem to misunderstand about LED is that they think because they are cooler that they can be put closer to the plant. this is not the case. LED diodes are pretty spectrum specific and there for one light fixture will have 7 to 9 different type of diodes to provide multiple spectrums that benefit the plants needs, but each spectrum travels at different wave lengths and to gain full potential for all the spectrums to be beneficial to a plant the light needs to be mounted roughly 250mm above the canopy. 

 

I personally don't use LED for my grow (I have in the past, but prefer the old school tried and true HID), but my knowledge gained of LED is from my Marine reef aquarium which I use LED exclusively for coral growth and health. And I better put a disclaimer out that you CANNOT use a marine reef LED to grow cannabis, they are tuned with different spectrums to provide health and sustainability for a different environment, its just the same concept. Even in the marine environment HID (metal halide) is far superior to T5 and LED, but MH over a marine tank in an Australian summer will give your chiller a workout and a half.