400w vs 600w FIGHT!!

currently runnin a 400w hps light but am wondering if i would benifit from upgrading to a 600w hsp my room measures 90mm x 70mmx 2.4m, will i see a increase of yield by say an ounce which is how much it will roughly cost as well as the extra power to do so??

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Fenda your measurments seem off:

90mm x 70mm = 3.5" x 2.75"

Centemeters would give you ~36" x 2'8", or 8.25 square feet. Your 400 watt HPS will give you the recommended 50 watts HID per square foot; the 600 watt will give you more light penetration into your canopy: 12" for a 400 watt and 18" for a 600 watt.

Can you vent the heat from 200 more watts?

How much bud do you consume? Do you need the extra production?

Another option would be to combine a light mover with your 400 watt, or even bumping to a 600 watt and building an 8'x3' grow cage if you need the production. Download the Equipment chapter of Weed Science (bottom of post) for some pictures.

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