Shagrathanswered grow question 4 years ago Hello!
In my last autogrow I used 2x2 tent and 2x120W quantum boards at full power but I had troubles with bleaching of the buds in the first flowering weeks and heat issues and also other light intensity related issues. So you can add more intensity gradually and see how they react to it, small bleaching is not that bad if treated right away so those small stress symptoms are the ones you have to look when given more light.
Without added CO2 you can probably use 65% without problems and maybe even 85% when in full flower mode