What could potentially my yield if i had 6 plants in a 100 x 100 cm room using the 90w ufo led grow light with co2 on a timer?
You don't want to use that UFO, especially for flowering. And I think 6 plants is too many for that light to begin with. I can not guess your yield, but it won't be too high. Also, a real CO2 setup is way expensive, and for CO2 to be effective, you need a sealed environment, and higher temps. You should start out reading all of the stickies on these forums. A lot of your questions will be answered. Good Luck.
I used a ufo led from seed, through grow and flowering and didnt have a problem. I used a 60watt ufo in a 0.60m x 0.60cm x 1.2m tent.
Good rule of thumb is one UFO per plant, I. Use this method and can yield 3oz per plant, 6 plants LOL good luck