i like how your using the lucas formula, ive recently been looking into it and it seems to be perfect for a lot of growers. what is your lighting system? looks either to be cfl or mh. the temps seem to be good but you may want to watch them and make sure they keep under 90F for your best results. your watching the PH which is another good thing, i dont even check mine haha. the fan situation is tough to choose and its more of the growers choice, you more need to watch if theres a temp change when the fan is set up differently. if there is alot of heat building up then it is probably better to have it exhausting out. if the fan keeps the lights cool and moves air around the plants when being set up facing them, then that might be the right choice. its always a good idea to have both an intake and exhaust if you can. what strain(s)?