Doesn't really appear to be light stress bro, I'm might as bold as to say 50 percent sounds like adquate enough lighting, you don't by any chance have a ppfd meter, if not can you tell me if you have and android based phone or apple because I know there is a free ppfd meter app called photone it's on the play store on android its not 100% spot on but it's not far off a real pprd meter tested it against my mates real ppfd meter it's only like 20 umols in the difference and it let's you select a meter for every type of light currently on the market today, also if you could get a humidifier in there ASAP or any other viable way of raising your humidity up to between 65-75 for optimal plant growth to thrive, best of luck bro this is all purely speculation but these little changes can be crucial to getting a fat yeald