u want to flower depending on ur light size a big plant under low wattage wont produce as much as a smaller plant under the same light so id low wattag flower it small.the plants looking good. i cant tell you if its indica or sativa yet soil has its own based ph so you dont have to worry about any of that. but when you do flower i would suggest using some nutes. even molasses towards of the end of your flowering gives you a 20% more yeild proven fact. flowering is your decision you dont really have a time that it needs to be flowered indoor just when ever you want the longer you wait the better it will be you could flower that plant right now if you wanted
but over all its looking good no burn spots or anything. but if you do start to see some burning get that foil outta their it holds heats its not like mylar or any of the other hydroponic shops hae that about it. get spray bottle if you havent already they like that and it will creat some co2